Imagine an illness that makes you feel ‘the same every day as an AIDS patient feels two weeks before death,’ but forever. It’s a real illness – and I’ve had it for a decade. I’m 25 now. It stole my whole youth. In revenge, I wrote a book, ‘Carnivore’ – that turned my hell into a thriller.

The words I quoted in my opening sentence were said by Mark Loveless, the head of the AIDS Clinic at Oregon University, while testifying to US congress. The illness he was testifying about has many names, some of which you may have heard of: fibromyalgia, chronic Lyme disease, myalgic encephalomyelitis (ME), and, worst of all – chronic fatigue syndrome (CFS).

Let me repeat that last one. Chronic fatigue syndrome. Imagine if AIDS was called ‘chronic fatigue syndrome’. It is an absurd insult. Most long-term diseases cause fatigue. But this disease being named after that symptom is one of the greatest injustices of modern medical history. And the main symptom I experience is pain, anyway – endless, inescapable, exhausting agony – in which my limbs feel like they’re being severed by saws, while my blood is being replaced by mustard gas – a pain so constant and overwhelming that I don’t feel like I belong in my own body anymore.

But due partly to its triviliazing name, ME/CFS has had barely any research funding over the last few decades. In contrast, billions of dollars have been invested in treatments for HIV. That’s why Dr Nancy Klimas, one of the world’s foremost experts in both HIV and ME/CFs, said in 2009: ‘I split my clinical time between the two illnesses, and I can tell you if I had to choose between them, I would rather have HIV.’

I watched my dad die of HIV, so I am familiar with its horrors. But the point of this comparison is to emphasize how unfamiliar the horrors of CFS/ME are to most people. Around 2% of all adults have my disease. But nobody knows how you get it, nobody knows how to get rid of it, and nobody is scared of it.

This is an invisible epidemic. And I wrote my book in the hope of making it more visible. I wanted you to feel what I feel. I wanted you to be scared.

But in addition to the horrors of chronic pain, I also wanted you to feel the giddy thrill of modern sexuality – the thrill of living despite a disease that wants to take your life away. A recent survey in the USA found that over half of teenagers identified as ‘not straight’. And that millennial fluidity is what I wanted to capture in my story too. I was tired of reading narratives of gay pain and gay tragedy; I was tired of watching queer secondary characters being killed off, while the straight mediocrities survived. I wanted to see the glamour, the excitement, the decadence of modern sexuality. So I wrote a queer coming of age tale, of a boy like me in a London like mine. And he knows what we all know, deep down, to be now true – that being straight is embarrassing.

On the night of my 24th birthday, I was staring at my bedroom ceiling, feeling just as terrible as the year before and the year before and the year before – with no change, no growth, no hope for improvement – trapped in barren lonely agony. I decided, like so many others with chronic pain, abandoned by modern medicine, to turn to heroin. And heroin gave me enough energy to write this book. My choice was between poison and silence. I chose poison, and gave voice to my illness – and gave voice to my hope for a queer future. If I cannot have my health, I thought, at least I can have my revenge – and transform this horror into the purest pleasure.

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Carnivore is published by HQ (Harper Collins), and is available in hardback and ebook on Amazon now