The first thing that went wrong was when I felt a strange sensation inside my head – a flickering, as though a butterfly was trapped inside, combined with tingling.

I didn’t know then about the physical effects that depression and anxiety can create. I just thought I was about to die.

And then I sank fast, falling into a new, claustrophobic reality. It would be more than a year before I’d feel anything like even half-normal again.

Why you must never, ever give up on life – by a man who nearly did
Matt Haig, left, with his two children, aged five and six, and his wife Andrea, right. Matt thinks that even 14 years past his lowest point, he still feels the echo of the mental illness today

It was 1999 and I was 24 years old. I was living in Spain with my girlfriend Andrea, and about to come to the end of six years of student life and summer jobs.

The weirdest thing about the human mind is that you can have the most intense things going on in there but no one can see them. No one seeing me in that villa in Ibiza could have appreciated the strange hell I was living through.

I stayed in bed for three days, but I didn’t sleep and barely ate. I can remember being stunned that I was still alive.

I know that sounds melodramatic, but depression and panic only give you melodramatic thoughts to play with.

On the third day, I left the villa and went outside to kill myself. The sun was beating hard. The air smelt of pine and the sea.

The sea was right there, just below the cliff – no more than 20 steps away. And the only plan I had was to take 21 steps in that direction.

In front of me was the most glorious view I’d ever seen. A sparkling Mediterranean, looking like a turquoise tablecloth scattered with tiny diamonds, fringed by limestone cliffs.

Yet that couldn’t stop me wanting to kill myself. I simply couldn’t feel like this a second longer. I had to end myself – and I was going to do it while my girlfriend was in the villa, oblivious.

Counting my steps, I walked. Then I lost count, my mind all over the place. ‘Don’t chicken out,’ I told myself.

I made it to the edge. I could stop feeling this way by taking another step. It was so preposterously easy – a single step versus the pain of being alive.

If you’ve ever believed depressives want to be happy, you’re wrong. They couldn’t care less about the luxury of happiness. They just want to feel an absence of pain. To escape a mind on fire, where thoughts blaze and smoke like old possessions lost to arson.

To be normal. Or, as normal is impossible, to be empty. And the only way I could be empty was to stop living. I stood there for a while. Summoning the courage to die, then summoning the courage to live. To be. Not to be.

Maybe there is a universe in which I took that step, but it isn’t this one. I had a mother, father, sister and girlfriend. That was four people right there who loved me.

I wished like mad, in that moment, that I had no one at all. Not a single soul. Love was trapping me here.

Also, if I’m honest, I was scared. What if I didn’t die? What if I was just left paralysed?

Why you must never, ever give up on life – by a man who nearly did
Matt was going to jump off a cliff in Spain – but his love for his wife Andrea and his family stopped him

I think life always provides reasons to not die, if we listen hard enough. And so I kept living. I turned back towards the villa and threw up from the stress of it all. Later, Andrea took me to a medical centre, where a doctor gave me diazepam. It didn’t work for me. Nothing lessened the relentless pain.

When I arrived back in Britain, my mum and dad were at the airport. ‘We were so worried,’ Mum said, plus 87 variations on that theme. Her smile had a slightly crumpled quality; her eyes were glazed with tears.

I felt the weight of being a son who’d gone wrong. The weight of being loved. The weight of being a disappointment.

We drove back home to Newark, Nottinghamshire, a place I’d only ever wanted to escape from.

Over the next few months I looked a bit slower than normal, but the experience going on in my mind was always oppressively fast. I felt as if I was trapped in a cyclone.

These were some of the other things I felt: like my reflection in the mirror showed another person; scared of being put in a padded cell; a continual sense of heavy dread; mental and physical exhaustion; like I was falling when I was standing still; an infinite sadness; loss of appetite (I lost two stone in six months).

And always the desire to step out of myself for a while. A week, a day, an hour. A second.

On top of depression, anxiety keeps you on guard to the point of collapse every single moment. That is not an exaggeration. You crave one moment of not being terrified, but it never comes.

One day I stood by a window. There were a few people walking along the pavement.

I prayed to be those people. Any of them. The 80-year-olds, the eight-year-olds, the women, the men, even their dogs. I craved to exist in their minds. I couldn’t cope with the sheer exhaustion of never being able to find mental comfort.

I cried. And not normal tears, either. These came from the deep. And once they came they couldn’t stop, even when my dad walked into the bedroom.

He looked at me and he couldn’t understand.

The tears were contagious. His eyes went pink and watery. I couldn’t remember the last time I’d seen him cry.

He hugged me. ‘Come on,’ he said, softly. ‘You can do this. Come on. You can pull yourself together, Mattie. You’re going to have to.’

My dad wasn’t a tough dad. He was gentle, caring, intelligent, but he still didn’t have a magical ability to see inside my head.

He was right, of course, and I wouldn’t have wanted him to say much else, but he had no idea how hard that sounded.

‘I’ll try, Dad. I’ll try.’

For the next few months, my parents would leave for work and then Andrea and I would have long days in the house. Life at the lowest possible volume that two 24-year-olds could manage.

People say: ‘Take it one day at a time.’ But days were mountains, a week was the Himalayas. The only real thing I wished was for time to move quicker.

I’d want 9am to be 10am. I’d want the morning to be the afternoon. I was as obsessed with time as some people are about money.

I stacked the days up like building blocks, imagining I was making progress, then – crash – along would come a five-hour panic attack.

One measure of progress was how far I could walk on my own. If I was outside and not with Andrea or one of my parents, I didn’t feel able to cope.

But rather than avoid these situations, I forced myself into them. I think this helped.

On days when I was feeling very brave, I’d say something impossibly heroic, like: ‘I’m going to the shop to get some milk. And Marmite.’

I’d leave the house as quickly as I could, trying to outpace the panic. By the time I reached the end of my parents’ street, I’d feel a deep insecurity.

Pain is a very isolating experience. We’re essentially alone – and when you’re ill, there’s no escape from this truth.

But let me tell you something. Something that sounds bland and drippy but which, I assure you, I believe entirely. Love saved me.

Why you must never, ever give up on life – by a man who nearly did
Matt credits his wife with saving him.

Andrea saved me. Her love for me and my love for her. Not just once, either. Over and over.

We’d been together five years by the time I fell ill. Please don’t think this was a perfect relationship. It wasn’t. It still isn’t. The months we later spent together in Ibiza now seem to be one long argument.

If you go deep enough under a tidal wave, the water is still. That’s what we were like. In a way, we argued because we knew it would have no fundamental impact. And when the depression hit, Andrea was kind to me and cross with me in all the right ways. The force and fury she’d once only displayed in arguments, she used to steer me.

She accompanied me to doctors. She got us into our own place in Yorkshire. She earned us money. She handled all the organisational side of my life. She filled in the blanks that darkness left in its wake.

She was my literal other half, when half of me had gone. She covered for me, waiting patiently during my absence from myself.

Then one day, four years after I’d first sunk into depression, Andrea announced a birthday surprise: ‘We’re going to Paris. We’re going to get the Eurostar.’

I was shell-shocked. I couldn’t imagine anyone saying anything more terrifying. ‘I can’t. I can’t go to Paris,’ I said.

It was happening. A panic attack. I started to feel it in my chest – that feeling of being trapped inside myself, like a desperate fly in a jar.

‘Well, we’re going. It’s going to be great. We’re staying at the hotel Oscar Wilde died in.’

Going to the place where Oscar Wilde died wasn’t making it any better. It just guaranteed I was going to die there in Paris, just like Oscar Wilde.

‘I don’t think I’ll be able to breathe the air,’ I said. I knew this sounded stupid. Yet the fact remained: I didn’t think I’d be able to breathe the air.

But Andrea knew what to do. She had a PhD in this kind of thing by then. She said: ‘OK, we won’t go. I can cancel the hotel. We might lose a bit of money, but if it’s such a big deal …’

Such a big deal. I could still hardly walk 20 metres on my own without having a panic attack. It was the biggest deal imaginable.

But if I said ‘no’, I’d be someone who couldn’t go abroad because he was scared. And that would make me like a mad person, and my biggest fear was of being totally mad.

So a big fear was beaten by a bigger fear. The best way to beat a monster is to find a scarier one.

I went to Paris. The Channel Tunnel held together and the sea didn’t fall on our heads. The air in Paris worked OK.

By forcing yourself into a new physical space you end up, inevitably, focusing a bit more on the world outside your head. Well, that’s how it worked for me in Paris.

Another thing that helped was running. What I liked was that many of the physical symptoms of panic – the racing heart, the problematic breathing, the sweating – are matched by running.

So while I was running, I wouldn’t be worried about my racing heart because it had a reason to race.

Each time I forced myself out into the cold, grey damp of a Yorkshire morning and pushed myself to run for an hour, it gave me a little bit of depression-beating power.

And, slowly, over the years, I built up other things that do, and began to find some success as a writer.

Yet even so, for ten years of my life I couldn’t go to a party without being terrified. I was simply unable to step into a room full of happy people without having a panic attack.

Shortly after I had my first book published, I felt obliged to attend a literary Christmas party. I headed into a room and instantly felt out of my depth as famous, brainy people seemed to be everywhere.

I held my glass of sparkling mineral water and, for a couple of seconds, I kind of accidentally locked eyes with the novelist Zadie Smith. She turned away.

She was clearly thinking I was a weirdo. The Queen of Literature thinks I’m a weirdo!

As I stood there, I felt a kind of annihilation. I began to be not entirely sure I was there at all, and I felt floaty. I needed Andrea. The air was getting thinner. I was lost in a black hole of my own making.

I got out of there. I left a coat in the cloakroom that could still be there for all I know. And I ran back the short distance to the cafe where Andrea, my eternal saviour, waited for me. ‘I thought you were going to be an hour,’ she said.

‘I couldn’t. I needed to get out.’

‘Well, you’re out. How do you feel?’

I thought about this. How did I feel? Like an idiot, obviously. But my panic attack had gone.

Back in the old days my panic attacks didn’t just go. They simply morphed into more attacks, breaking me down until depression could come in and colonise my head.

But no. I was feeling quite normal again. A normal person who was allergic to parties. Really, I’d just wanted to escape the room.

It’s a weird thing, depression. Even now, writing this with a good distance of 14 years from my lowest point, I haven’t fully escaped.

You get over it but it comes back in flashes, when you’re tired or anxious or have been eating the wrong stuff, and catches you off guard. I woke up with it a few days ago, in fact. I felt its dark wisps around my head, that ominous life-is-fear feeling.

But after a morning with our children, aged five and six, it subsided. It is now an aside, something to put brackets around.

And so I’ve gone from never feeling happy to feeling happy most of the time. Even so, I’ll always have a thin skin. But would I really want a magical skin-thickening treatment? Probably not.

Why you must never, ever give up on life – by a man who nearly did
Matt Haig, left, with his two children, aged five and six, and his wife Andrea, right. Matt thinks that even 14 years past his lowest point, he still feels the echo of the mental illness today

You need to feel life’s terror to feel its wonder. And I feel it today, actually, right now.

I feel the sheer, unfathomable marvel that is this strange life we have, the seven billion of us, clustered on this pale blue dot of a planet, spending our allotted 30,000 days as best we can.

I like to feel the force of that miracle. I like to burrow deep into this life, and explore it through the magic of words and human beings. And I’m glad to feel every tumultuous second of it.