I began using HRT patches at 42, after a seemingly catastrophic breakdown that resulted in my climbing into a Sainsbury’s fish-finger freezer. My mental health was horrendous. I felt totally outside my own skin, dissociated, and that I’d lost my sense of self. I told a therapist that I related to Mrs Dalloway, a chronically depressed – and arguably narcissistic and bourgeois – fictional Virginia Woolf character. She suggested that these feelings could all be down to perimenopause, a term I’d only heard of vaguely, in passing, even as a former nurse. Perimenopause, she told me, can be an extremely rocky road, lasting up to a decade before menopause itself.

My GP didn’t bat an eyelid at my bizarre symptoms, but offered me low-dose HRT patches and described the side-effects as minimal in most people. Some women experience breast tenderness or feeling sick, or headaches but, she said, this usually settled down. I hoped the patches would lead to fewer perimenopausal symptoms and a balancing out of my mood, some comfort and at least some realism.

Instead, within 24 hours of putting on a patch, I suddenly started thinking about sex all the time, a side-effect I was not expecting. I was totally perplexed by this midlife sexual awakening – and more than a little disturbed by it. At midlife, it felt strange and wrong to be obsessing about sex so much. I’d imagined lust and desire would creep away, leaving me with other pursuits, like gardening. I anticipated losing interest in romantic love, or at least, confidence at midlife, identifying with psychotherapist Susie Orbach’s description of it: “Some find the decline of youth and beauty a source of grief and shock. Meanwhile, the menopause arrives, seeking out our vulnerabilities, like a guided missile, just as we need all our strength to cope with daily life.”

But as well as being absorbed with the stresses of daily life, I was walking around with a burning body and a mind like an erotic playground. I was confused and disoriented. Like everyone in our culture, I’ve been spoonfed the narrative that sex resides in the Kingdom of the Young, and the Kingdom of the Well. Everything I’ve ever seen on television or in films confirms what Lynne Segal, Birkbeck anniversary professor emerita of psychosocial studies, wrote, that “while signs of physical ageing are routinely downplayed in leading actors, who regularly take the roles as still vigorous and desirable characters (whether heroes or villains), the opposite applies to older actresses, if they are allowed to appear on screen at all”.

Surely, as well as the clear misogyny of the absence of older women on our screens, there was nothing at all sexy about ageing. I’d read about (and was starting to experience) some of the symptoms that can affect women’s sex lives at midlife: vaginal dryness, atrophy, difficulty achieving orgasm, weak bladder, tiredness, insomnia, depression, low self-confidence… 42 was clearly not a good time to have any kind of sexual awakening. And yet something propelled me on, a kind of raging against the idea that I was done with desire. I was lucky enough to be surrounded by love, with a rich life full of friends and interests, but the unexpected side-effects of my HRT patches reminded me that I wanted a romantic relationship, too.

Understanding both what I wanted or needed and the links between sexuality and ageing was not straightforward. Like many of my midlife friends, I was also single when all this began and navigating dating as my body (and mind) fell apart in dramatic ways. In her book Why We Love, the anthropologist Helen Fisher suggests that dating is a game designed to “impress and capture”, one that is not necessarily about honesty but novelty, excitement and even danger, which can boost dopamine levels in the brain.

All this might have appealed to my younger self, who wanted to be anyone but me, frankly, but in my 40s I was craving authenticity, truth and the ultimate goal of being comfortable in my own skin. I wanted the true intimacy that comes with being open, warts and all – what psychotherapist Esther Perel calls “into-me-see”. But I also understood that a dating profile that read “slightly unhinged perimenopausal woman experiencing hair loss and vaginal dryness, seeks secure, loving partner for fun times” was not going to get many hits.

Online dating felt like a world full of avatars, where I projected a more polished, shinier version of myself to someone who projected a shinier, more polished version of themselves. It was all so fake. I wasn’t interested in hookup culture. I’m way too intense and I really wanted to find a partner who I could spend my life with, one who’d accept my vulnerable, raw, full self and not be deterred by my perimenopausal symptoms.

But was this really a time to find a new partner and at some point be naked in front of them? I felt weird and embarrassed by my changing body, a feeling Nora Ephron reminded us of in I Feel Bad About My Neck. “Anything you think is wrong with your body at the age of 35,” she wrote, “you will be nostalgic for by the age of 45.” I was deeply nostalgic and wondered if I’d simply missed the romantic relationship boat. I began to wonder if I should simply give up on the idea of a future sex life and try gardening instead. But then I remembered.

When I was a student nurse I worked part-time in a care home. It is decades since then, but I still remember one of the residents, Edith. Most of the people in the home were, to me, impossibly old. They had extensive physical needs andseemed to do very little other than sit in the television room, almost catatonic. Except Edith. I remember her laugh, the glint in her eye, mischief. She wore leopard-print slippers and bright lipstick and smelled of hairspray and lavender. One evening, we did a pub quiz for the residents and Edith sat with her team, Gareth and Frank, two quiet gentlemen who had lots of health issues, which made them fairly reliant on the care home staff. When they won it was a total joy to see their faces light up as though they’d won the lottery, not just a bottle of sherry.

Later that evening I was doing the tea and coffee rounds and Edith’s bedroom door was locked, or blocked from the inside. I started to panic. Death was not uncommon in that place and illness or an accident never far away. But I managed to push open the door and Edith was not dead. In fact, she was sitting up, laughing in bed, semi-naked. Nor was she alone. Gareth and Frank were also in her bed… also semi-naked.

Of course, I am not now and never have been as sexually liberated as Edith was at 95. But my relationship with sex, along with my relationship with everything else (bodies, dating, parenting, wisdom, death, love) is changing rapidly at midlife. What a joy it was recently to watchthe hilarious and important Good Luck To You, Leo Grande and cheer as Emma Thompson’s character comes to realise that good sex is not at all about young bodies. It’s about being comfortable in your own skin, whatever age you happen to be. That we are witnessing this change in attitudes towards ageing on our screens and off feels radical and liberating. Ageism remains prevalent in our society, but watching older characters being sexy on screen feels like an important change.

The novelist Isabel Allende, in her Ted Talk “How To Live Passionately – No Matter Your Age,” said, “Inside, I feel good, I feel charming, seductive, sexy. Nobody else sees that.” I see that. Perhaps all of society is starting to see that, and about time too. Because it’s a beautiful truth that desire and passion and sex reside just as beautifully in the Kingdom of the Old and also in the Kingdom of the Sick. And even very old people enjoy sex, and for many people, like Edith, sex just keeps getting better. It becomes less about bodies and more about souls, perhaps.

I was way too intense and confronting to casually date, but with the help, in my case, of HRT, along with therapy and a deep dive into selfhood, I learned to love myself a bit. And when I stopped obsessing, or looking outward, or looking at all, I did find romantic love. I am now 45 and my boyfriend and I have been together for 18 months. He really does love me, exactly as I am. It’s wildly unnerving. From him, I’m learning about love. And Edith was always wise, too, reminding me of what is possible as we age, whatever approach we have to life. I am very different to Edith. Almost prudish, comparatively. For her, sexuality was about raucous fun. For me, these days, I’ve come to understand sex as a spiritual act, two people seeing inside each other, a flicker of something intensely and uniquely human, a flash of humanity. Edith and I are both right. There’s everything to look forward to.

Some names have been changed. Christie Watson’s latest book, Quilt on Fire: The Messy Magic of Midlife, is published by Vintage at £16.99. Buy it for £14.78 at guardianbookshop.com