I proposed before I kissed my wife, which was probably just as well: she was dating someone else at the time. Our own connection was immense, seemingly unshakeable and, ultimately, isolating.

We had a “bubble relationship”. Just us, not so much against the world, but in a marriage where we moved as one, happy together, not needing anyone else. It worked like a dream, until it didn’t. Relying on just each other is all well and good until the cracks begin to show.

The first sign was in times of conflict. When we argued, I would isolate myself even more. Not easily trusting men, and never building friendships with them, left me alone at exactly the moments I could have had support. She had her girlfriends a call away. I had her. I think that’s why I was always the one who apologised first and defused the tension – I needed my support back, and she was all of it.

Over the years we narrowed our friendship group down, whittled to a few girlfriends in her case, and literally nobody in mine. When my mum became ill, I isolated myself again, predictably perhaps. When she died, my wife tried to support me, but it is hard to be a lover, partner, housemate and support all at once. She tried. I hid. My fault.

When things went south and I left, I was quickly thrust from being a man who needed no one (except the one) to facing the stark reality that I was alone. I’ve never been one of the lads. I’m easy enough in male company, but I’ve never felt much desire to cultivate those wider friendship circles. The friendships I did have, with women, were the ones I picked back up after the split, and they are what got me out of that flat. I am not alone. A lot of men who live in a bubble relationship have no one else at all.

I give relationship advice to thousands of women each week, and a lot of the calls I get are from wives wanting to know how to help their husbands become less reliant on them. One woman recently told me her ex-husband couldn’t let her move on. He kept appearing. In messages, calls, small questions that didn’t need asking, the occasional late-night outpouring she knew she’d have to answer.

She had been everything to him. She was the contents of his phone. She was the friend he had always relied on, the person he would celebrate with and the person he would moan to. What he was losing wasn’t the romance, or even the marriage. It was his only real ally, finally pulling away after years of being everything to him.

She’s far from the only one. Women still in their marriages tell me the same about their husbands, and so do women who left years ago. There’s no friend he’d confide in, no one he’d ring if something went badly wrong. There’s only her.

It rarely starts out as a problem. In the early years, being each other’s whole world feels like the point – I know, because I lived it. But over time men let friendships go, work takes over, and the friends he had aged 25 become people he sees at weddings, or worse, funerals. Her friendships tend to survive because she kept them going. Twenty years on, she has a circle, and he has only her.

Women become their husband’s therapist, social secretary and his only witness. They absorb his bad days. And underneath sits a quiet, constant worry: if you step back, who will be there to save him? I’ve met women who stayed years, decades longer than they wanted to, held there by exactly that.

When the marriage does end, the man often falls apart in a way his ex-wife finds baffling. She’s lost a husband. He’s lost his wife, his best friend and his entire support network in the same afternoon. So he finds his way back to her. The messages aren’t about the bins or the bank account. They are a man reaching for the only person he’d ever reached for.

Whether it’s during a marriage or after it has ended, women tend to do what they have always done: fix things. They book him a round of golf with the neighbour. Nudge him to ring his brother.

I understand the impulse, but it almost never works. It turns his friendships into one more job you’re doing for him. Men need to learn to find their own way. They tend to bond side by side rather than face to face, so join a five-a-side, a running club, help someone move a sofa. Telling them to “go and talk to someone” goes down like a cup of cold sick.

Letting other people into the bubble gives you a much stronger foundation to build on, and a much kinder legacy to leave behind if it ends. My own bubble really was glorious, but I learned in the hardest way that the best thing you can be for someone you love is not their everything.