I was sitting on the bathroom floor, sobbing. The room was spinning. It was the heart of lockdown and I wasn’t coping – or, rather, I was attempting to cope by drinking heavily. My nascent alcoholism, bobbing at a functional level since I was 14, was finally dragging me under.

Beneath the hopelessness was utter self-loathing. As a full‑time crime author with eight published books under my belt, I had a packed schedule – editorial deadlines, publicity commitments – and, on top of it all, the next morning I had to home school my two small kids. Deep down, I already knew that tomorrow would be a write-off. My alcoholism had been like a hard seed, digging uncomfortably into my life for the past 25 years. Now, it was blooming into a blowsy acceptance. My addiction was killing me. The worst thing was that I didn’t care.

The next morning, hungover and shot with anxiety and shame, I made the call that would change reality as I knew it: I booked myself into rehab.

My memory of what happened next is hazy. Checking in while still clamped in the sweaty embrace of alcohol withdrawal was a horrible blur. Alongside the humiliation of being searched for drugs and the ringing shame of admitting my addiction, I remember the gothic styling of the building, with a lot of carved wood. It’s hard to describe the strange juxtaposition of a facility that is luxurious yet clinical.

In that moment, I felt caught between two worlds: one where I would die and another where I would live a death-like life. Each felt equally unbearable. In the end, it wasn’t a choice at all. My shaking limbs and rampant nausea made it physically impossible to do anything more than stay the course. So began the endless schedules, classes, group therapies and shared living of rehab.

Over the next few days, I gradually adjusted to life in the clinic. With the help of counsellors and other patients, I started the hard work of unpicking the path that had brought me there. I kept a journal at the time and, looking back now, it reads like the words of another person. “I started drinking too heavily because I couldn’t finish a book,” I wrote with naive assurance during the first week.

Back then, I thought the reason for my addiction was obvious. Almost a year before my lowest point, an appalling tragedy had struck my family – something so unbearable I still struggle to put it into words.

I had already been taking the most disturbing events from my life and trapping them in crime thrillers. My novels drew deeply on my own emotions – it was how I got material, but it was also what I used alcohol to numb. Alcohol became my creative anaesthetic.

Now, though, it wasn’t working. This new trauma had struck so deep that the alcohol couldn’t reach it. I needed to write about how I felt, but the words died on the page. I drank more and more, then despaired as the book that ached to be written floundered, unable to draw breath.

A few days into rehab, I shared this “cause” of my uncontrollable drinking with the small selection of addicts with whom I had been assigned group therapy. Not one of them was convinced that my “couldn’t finish a book” diagnosis even stroked the surface of my problem with alcohol.

When a wonderful young doctor and ex-cocaine addict whom I’ll call Liz voiced this in group therapy, I finally questioned my own spin.

“You drank a lot before that happened,” she pointed out. “A long time before.”

Liz was right. It brought me up short – initially in a thorny and resentful way, later with expansive gratitude. The truth was that I was using my recent tragedy to hide; my addictions had started in childhood. But admitting that meant recognising the frightening fact that I had never experienced adult life sober.

That night, in the room I shared with Liz and another former addict, I started writing in my journal for real. I began to poke at the shreds of truth that I had been hiding from myself. Ghosts of childhood memories took on solid edges and, along with them, some fledgling threads of the book I had previously struggled to write began to emerge, a smatter of green shoots poking through dark soil.

The next day, I shared my revelations with my counsellor – a former alcoholic with a caustic, no-nonsense style. My addiction, I ventured, went back to my school days. She greeted this with a small smile. “Congratulations,” she said. “I was wondering when you’d figure that out.”

* * *

For the first time, we began talking about my younger years. I couldn’t stop crying. Between sobs, I explained how my childhood had been relatively “normal”: I had had loving parents and a safe home. Nothing to complain about – except for the fact that one parent was an alcoholic and the other was addicted to their work. This combination gave me a bone-deep addiction to overachieving and an abandonment complex that hovered, spectre-like, over every human contact.

Then came secondary school – a violent bear pit of feral teens who drank whisky at 8am on the school bus and hospitalised academic kids like me on the way home. I quickly adapted. By 13, I smoked, drank and sought out drugs as if I was working my way through a hedonistic bucket list.

By 14, I had taken acid, speed and every type of prescription pill. I would skip school to inhale thick drafts of cannabis on an almost daily basis. Low on cash, I started shoplifting to fund my habits – a memory that fills me with terrible guilt and shame. When I was 15, I travelled cross-country to Glastonbury festival, alone for nine hours on packed trains and buses, swigging lager and smoking all the way.

But, for all my swagger and independence, I was oversensitive, struggling with relationships and bolting at the first sign of abandonment. I dismissed people without addiction issues as “boring”, never realising how uninteresting alcohol-induced emotional torpor made me.

For all the utter chaos inside, outwardly I held it together. Only someone who looked very closely would have seen the tape and string. My addiction to overachieving meant I got straight As at school, followed by a first in English at university. I even won a prestigious scholarship to take an English MA. By the time I left university, I was freelancing full‑time for newspapers, covering a mixture of travel, lifestyle, finance and, ironically, health. True, I couldn’t hold a romantic relationship; any suggestion of commitment paralysed me with fear. But no one would have looked at my life and imagined the vast, loveless void at the heart of it, a hunger pulling everything into its vacuum.

In my 30s, I was able to out‑wrestle my commitment phobia just enough to find my soulmate. Two beautiful children followed. I would love to be able to tell you that my deep adoration for them cured my addiction. But it didn’t. In fact, a mixture of postnatal depression, combined with my insatiable work addiction, dragged me lower still. While I didn’t drink during pregnancy, I managed to find test strips for breastmilk online so I could check my milk was alcohol-free before feeding. Even then, I didn’t accept that alcohol was a problem.

Years of denial were broken down and dissected over 30 days of rehab, the painful memories of my addiction drawn out like poison from a wound. For more than two decades, I had stitched my emotions under a thick jacket of addiction. Now, the jacket had been turned inside out and I was wearing my most tender feelings on the outside. It was absolutely excruciating, as if someone had sandpapered away my skin, revealing a wall of open nerves. I was experiencing feelings I hadn’t felt since I was 13, because, emotionally, I had never really grown up. It was a realisation I found embarrassing and fascinating in equal measure.

I started to remember fragments that I had forgotten; I didn’t know what was real and what wasn’t. At the time, it was incredibly frightening. I sweated, I shook, I struggled with the overwhelming desire to walk out and down a bottle of wine.

Slowly, I got better. The shakes and anxiety switched to clarity and calm. By the time my stay drew to a close, I felt like Sleeping Beauty, awaking from a 100-year slumber. I was 40. What a lot of time I had wasted.

But what a lot of time I had won back, too. I entered rehab broken, using alcohol as my armour. When I left, I wasn’t alone and afraid any more. I had taken my first steps towards asking other people for help when I needed it. I felt as if I had changed on a cellular level. But I knew there was a long road ahead.

Deep down, I feared I would never be able to write another book. Then, several months into recovery, something happened that I could not have expected. The book that I hadn’t been able to write, the one that I believed to have been integral to my undoing, suddenly bloomed into being, inspired by the experiences and people I had met in rehab. Struck by the notion of setting the action inside an addiction clinic, everything came together. The half-built chassis of a manuscript was given wheels in a way I could not have predicted. I told my agent I wanted to write a murder mystery set in rehab. I called it The Clinic.

This was the first book I had written sober – and by far the most terrifying for it. It was only when librarians across the US voted it among their Top 10 reads for this month that I breathed a sigh of relief that I didn’t realise I had been holding. Perhaps it was possible I could write without using alcohol. With that promise, another door opened.

The Clinic by Cate Quinn (Orion, £22) is out now. To support the Guardian and the Observer, order your copy at guardianbookshop.com. Delivery charges may apply

• In the UK, Action on Addiction is available on 0300 330 0659. In the US, call or text SAMHSA’s National Helpline at 988. In Australia, the National Alcohol and Other Drug Hotline is at 1800 250 015; families and friends can seek help at Family Drug Support Australia at 1300 368 186

• In the UK, Samaritans can be contacted on freephone 116 123, or email jo@samaritans.org or jo@samaritans.ie. In the US, you can call or text the National Suicide Prevention Lifeline on 988, chat on 988lifeline.org or text HOME to 741741 to connect with a crisis counselor. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at befrienders.org

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