I've always been a diarist. I used to be a journalist and travel writer; writing was part of my everyday life. So from the moment my pancreatitis hit in 2004 until the day I staggered out of rehab six years later, I wrote about it. I did so because it felt natural, but also because I knew that there was something extraordinary about it. It was all so extreme.
At that time, halfway through 2004, I had been feeling quite tired, and had a lot of backache. So I went to my doctor. He gave me a leaflet on how to deal with muscle pain. But then one day, bang, that was it: the most amazing pain. By seven o'clock that night, I was in A&E, and my life would never be the same again.
It took several weeks for the pancreatitis to be diagnosed. My surgeons later described it as the wild west of modern medicine. Not much is known about it and not many surgeons like to deal with it because it is so difficult to treat. It also brings their survival rates down.
I was told it is the most pain a human can endure. On the pain Richter scale, childbirth is between five and six, pancreatitis around seven and eight. Hence the need for massively strong painkillers. I was put on painkillers from the start, initially a stronger version of ibuprofen. A few weeks later, it was discovered I had been given the wrong kind of opiate, which only exacerbated my situation. It was then I was put onto fentanyl, an opium-derived pain reliever almost 100 times stronger than morphine. NHS guidelines dictate that the maximum amount you should take – in the form of lozenges – is eight a day. I ended up on about 60.
But there is no doubt that fentanyl saved my life. When you are in that much pain, you can die from it. I was told that each attack of pancreatitis was the equivalent of a heart attack. Over a three-and-a-half-year period, I had 40 attacks.
I was 33 years old and it had come out of the blue. Alcohol can sometimes prompt it, but in my case, it was a genetic condition just waiting to erupt. I had to stop working immediately. The flat I had just bought I had to rent out and I went to live with my parents, who looked after me. I did have a little nest egg, which took me through the first 18 months of the illness, but after that I had to apply for incapacity benefit. I developed ME as well and could barely leave the house. I was in incredible pain and extremely tired. All the time.
The yearning for fentanyl quickly became something I couldn't control – the craving, the shaking as the withdrawal pangs took hold, the relief when I opened another lozenge. For a long time I had nothing except for the drugs, day in, day out. It was awful to be so physically dependent, of course, and I try not to think about it today – but now and again, I'll be really honest, I miss it, and think: wasn't life so much simpler on it?
But the fentanyl did alleviate the pain. It helped. It affects the opiate receptors in your brain, and removes perception away from pain. It's like having a blanket that settles on you. It brings you down, the pain slips away, everything goes foggy and softly tinted, and you feel woozy and a bit high.
I have to admit that I didn't do any research on the drug, or its dangers, beforehand. I was too ill, in desperate pain, really clinging on for my life. All I cared about was that it was working. When you are in that kind of pain, nothing else registers. I was so relieved that there was something that would get me through all the hours and days, that's all.
Even though fentanyl is incredibly strong, the body learns to metabolise it. You get used to it, and so you need more. I went back to my doctor for more and more, completely and utterly dependent on it for my survival. My GP knew within eight or nine months that I was addicted and spent a long time telling me so, but I wouldn't have it. I refused to listen.
Once I did accept I was an addict, I went into rehab. They said they had never seen someone on such a high does of Fentanyl before. It was so hard to get off them but I did. I'm a member of a 12-step group now, which is a spiritual programme. I'm not sure whether I'm religious myself, though I do feel spiritual. The way I look at it, I must have been helped through all this by something: fate, luck, a guardian angel. Who knows? I just don't see how I could have survived without a bit of help. For a long time, I was a self-pitying victim, but then I realised that half the world has to deal with being ill, and so basically I got a grip. I started to laugh at myself, or at least try.
These days, I live every day as it comes. I still have pain, still have fatigue issues and I live with disabilities. Pancreatitis is a recurring condition, so it could strike again. I am aware of that. I went to my specialist just last month and was told that I have to be grateful for every day that I am well. People die from this condition.
But I am making a life for myself, learning to live without fear but with dignity and even an eye to my future. I've found myself a husband and I have a stepson. I live in a lovely little house – and I've written a book. So, yes, today is OK. Life is good.
Interview by Nick Duerden
'Painkiller Addict' by Cathryn Kemp (Piatkus, £13.99). To order this book for the special price of £12.59, including P&P, go to independent booksdirect.co.uk
A hidden addiction
* Fentanyl is an opoid analgesic, one of a class of powerful drugs, often prescribed for severe chronic pain.
* Their use has grown over the last two decades, with a six-fold increase between 1991 and 2009, partly due to an ageing population more likely to suffer from chronic illnesses.
* As patients develop tolerance to the drug and it becomes less effective, doctors often increase the dose, until patients are taking many times the recommended dose.
* Consequently, addiction is likely to be widespread, and the National Treatment Agency for Substance Misuse has expressed concern. But there is little data regarding the extent of the problem.