I’m eating a gammon and hummus croissant in my mother’s kitchen and wondering if I’m happy. The room itself is depressing. Half-finished as long as I’ve known, wooden cladding that ends abruptly along one side, freezing hole in the wall next to the washing machine. At the hob, my mother is gossiping about some odd-sounding people she’s met. “He was Ham… something, and his sister Amelie. They were abducted and she was seduced. I can’t remember by whom.” She does this, bumbles into stories ill-prepared and halfway along, dropping in names I’ve never heard. I ask if these are friends of hers from work. “You silly boy. It is a novel. The Great Yarmouth novel. Will text you when I remember.”

She’s not a believable character, I think as I observe her. This is ironic because I recently wrote a book about our relationship, and my mental health. (It’s also about trauma, family secrets, acting, sex and an anatomical ignorance of ducks, because books are lots of things at once.) I’ve been having a hard time since it came out. Not because the response has been bad – the opposite, in fact. There were rave reviews, a sold-out launch. The memoir became a bestseller, and heroes got in touch to tell me I was a genius. A wildly unrelatable anecdote, I know. The thing is, it’s unrelatable to me, too. I’ve never known how to process good news, or react to it. A connoisseur of failure, I was wrongfooted by success.

Suddenly it felt like everyone was talking about someone else. I’d call it imposter syndrome, but I don’t think I’ve earned that diagnosis. It’s more surreal, like I’ve quantum leapt into a strange body. Or as if a heroic runner has built up a lead, then accidentally passed the baton to some fool who wandered on to the track. There’s me, bewildered in short shorts, only got up to stretch my legs and now this.

I know I’ve been confusing people by not cartwheeling to the corner shop every morning. They bound up and tell me I must be delighted, as if they’ve never met me. I look up at them, needy, ashamed and obscurely confused, the way a dog makes eye contact when going to the toilet. It’s a disorienting thing, to be celebrated for pain. As if one could obliterate the other. Anxiety doesn’t take a holiday. For me, peak experiences come loaded with an inbuilt sense of future regret; the sly leeching away of libido as you wonder if everything is a downward slope from this point on.

It makes me think about all those other happiest days of our lives. Weddings, birthdays, giving birth. The day you graduate, the day you retire. All these experiences have loss in them, yet we often feel that any response other than ecstasy constitutes ungratefulness, even a betrayal. We don’t like to look out into the crowd and see our ambivalence there, or our private grief, side by side with our joy. It’s like running into an ex at a bake sale.

It doesn’t mean that enthusiasm-deficient people like me are unhappy though. We expend energy worrying about whether we’re feeling it enough, or mired in guilt about disappointing others. Our cheeks hurt. But we’re not wrong to feel mixed up. Inconvenient feelings will have their due. It’s arguably unnatural to feel one emotion; when life is lots of things at once. It works both ways, too. I remember when my father died, I had to sign for a probate letter addressed to “Rhik Sadder” and I laughed so hard at that. Experience is complex and layered like… a Vienetta. A concertina of dark and light, sometimes with a mint filling. I believe Iceland also stocks a knock-off version on a stick.

As with that last paragraph, the trick is knowing when to stop. (The abuse of metaphor was itself a metaphor? We’ve got a maverick on our hands, boys.) This is what I’m trying now. To stop policing my feelings, and accept them all. To stop presuming at the emotional reality of others, when they tell me their good news. To stop imagining good cheer to be a simple thing. I’m comforted by the words of pianist Oscar Levant, who wrote: “Happiness isn’t something you experience, it’s something you remember.” Letting yourself off the hook can do wonderful things.

I realise that there are times I feel a little warmth in the chest. When other friends look me in the eye and say that, regardless of how I feel, they’re proud of me, something thaws. I’m pleased to have such people around, who feel things I can’t, and translate for me. Who check in unjudgmentally. Of course, some of these people are so bizarre themselves, any sort of normal response would be moot anyway.

Late the next evening, when I’m alone in my home and wondering what the future holds, my phone vibrates. It’s a text from my mother. “David Copperfirld,” it says.

I Never Said I Loved You by Rhik Samadder is published by Headline at £14.99. Buy a copy for £11.99 at guardianbookshop.com