As a child, I remember being pretty certain about a few things. I was sure I’d get married. I was convinced I’d write a book. Then I’d have children – two, of course, just like my parents. Preferably girls because they were better.

When you’re younger, you assume life will turn out a particular way because you haven’t lived it yet. It sometimes strikes me that getting older is a gradual erasure of the nonchalant confidence that comes with that naivety.

For much of my childhood I was weaned on a diet of romantic love. The happy coupling between man and woman was the end-goal of every schmaltzy 1980s film. The photo-stories I read in teenage girls’ magazines all involved a boy whose attention they wanted to grab. On Neighbours, the wedding of Scott and Charlene in 1988 was an event of grandiose proportions. At school, we measured out our popularity in the Valentine’s cards and long-stemmed red roses we received on 14 February. I developed furious, unrequited crushes on boys who never noticed me in the way I wanted them to.

Later, when I went to an all-girls boarding school, I covered my wardrobe with ripped-out pictures of Levi’s models and Brad Pitt in A River Runs Through It. Everyone was obsessed with Take That. I once wrote a fan letter to Robbie Williams, including some Russian phrases I’d learned, in the hope it would make me stand out, not realising that my mastery of the Cyrillic alphabet wasn’t going to make a globally famous pop star fall in love with me when I was 14 and still wearing DM boots with purple laces.

Throughout the 80s and early 90s, the mainstream pumped out this theory that there was only one way to be loved and validated, and it was a straight, heterosexual, man-woman partnership. This was the era before gay marriage became legal, before the necessary acceptance of gender fluidity and the trans community, all of which are comparatively recent progressions that have made our lives so much richer and so much less binary.

But it’s strange how, despite being so liberal in my outlook in other respects, I adhered for so long to the notion that true happiness existed only when you found a partner and settled down to a family life. In my 30s, it’s what everyone else seemed to be doing: they were buying Bugaboos and going to church to get their kids into a faith school and moving to leafier parts of London because a café had just opened down the road that did good flat whites and organic seeded sourdough. Unthinkingly, in the grip of some sort of collective middle-class hypnosis, I tried to follow the herd.

I pursued my childhood certainties: I did get married and I did write a book (four, in fact). But in other ways things didn’t turn out quite how I’d imagined. I didn’t have children. I went through two failed cycles of IVF, followed by a natural pregnancy during which a scan revealed a healthy heartbeat at seven weeks and we were told confidently the chances of miscarriage were now less than 5%.

But the weeks passed, and it turned out I was part of that 5%. At three months, I miscarried. It’s a strange word, isn’t it? Miscarry. As if losing a baby were a matter of carelessness: a bag of grocery shopping I was unable to lift.

The miscarriage caused a gradual implosion of self. I got divorced. I left the country. I changed jobs. Everything in my life was in flux apart from one constant: my friends. It was my friends who rallied round and picked me up and were there at the end of the phone line whenever I called. It was a friend who dropped everything to come to the hospital when I needed her. It was a friend who gave me somewhere to stay, refusing to take rent until I insisted and even then, not allowing me to pay nearly enough. It was a friend who told me I was going to be OK and allowed me to believe her when I no longer believed in myself. It was a friend who gave me a T-shirt emblazoned with the words “Rock Solid” because, she explained, “I’m rock solid for your future and I know you’re going to be OK”. It was a friend who poured me glasses of red wine. A friend who passed on the details of her therapist. A friend who took me out to watch Magic Mike XXL. A friend who helped me move house. A friend who hugged me close and helped me through one of the scariest, most emotionally draining times of my life.

My friends helped me survive. Without them, I honestly don’t know where I’d be now.

When my marriage ended, I realised that another kind of life existed. It was one in which I got to know myself a lot better and where there was freedom in choosing not to conform. For a long time, I felt I had failed to be a wife and failed to be a mother, and that these things spoke badly of me as a person. I had tried so hard to put a positive gloss on things and keep going that I was ashamed when this facade crumbled. But it was my friends who made me realise this was nonsense. They preferred me as someone who made mistakes, as long as I was honest about them.

“It’s more real to fuck up,” my best friend told me one day. “You don’t have to try to be better than you are, because who you are already is why I love you. The real you. Not the you where you are pretending to be someone and tailoring all your needs just to make other people happy.”

In the aftermath of divorce, I tried to be myself. That sounds trite, but what I mean is that I tried to feel good about who I was, on my own, without the scaffolding of the romantic relationship I had always dreamed of.

It didn’t happen straight away. I got into another relationship that ended last October, even though I had made different decisions this time; even though I had worked so hard to be honest and open to another way of being. The break-up was tough. Once again, my friends stepped in. Once again, they held me close and told me they had faith and built me up with love. Once again, I was reminded of how incredibly lucky I was to have them. Once again, I got over it and emerged far stronger.

Unlike my romantic partners, my closest friends have never once let me down. My friends are the people to whom I never have to explain or make excuses. They accept me for who I am, whether we’re eating a takeaway in front of Queer Eye or drunkenly requesting Salt-N-Pepa’s Push It from some startled DJ in the middle of the night. It’s why I’ve dedicated my latest novel to them: a permanent reminder of how much I love them.

These days, I’m more comfortable with the realisation that I don’t know how the future will pan out. I’ve learned that life is sometimes confusing, often messy and always surprising. To pretend otherwise is to kid yourself you have control, and that means you can’t possibly hope to experience anything authentically. If you’re trying to shape what happens next, you are probably not paying enough attention to what’s happening right now.

By consciously attempting to quell all those fears, hooked to a future that doesn’t even exist yet, I’ve got better at just being. I suppose the best way to express it is to say simply that I’ve started feeling more “me” than I ever have before. I think I’ve got back some of that childlike confidence in myself. That’s due, in large part, to having friends who have taught me I am enough, just as I am, without trying to be something else.

And if I do ever have a freak-out about where on earth this colossal gamble called life is headed, I pick up the phone and I call one of them and we will talk and probably laugh and maybe weep and when the conversation ends, I will feel less alone and happier and more confident that there are good and beautiful things in this world.

I know I can rely on my friends. This is a gift. It makes me feel that whatever life holds, I will be OK. Better than OK, in fact, because just as I imagined all those years ago, I am part of a great, lifelong love affair. Not with a man, but with the people who have been there for me all along, if only I’d stopped to notice it sooner.

To order Elizabeth Day’s latest novel, The Party (£8.99, 4th Estate), for £7.64, go to bookshop.theguardian.com