Teaching is a stressful job. It is difficult, complicated and energy-sapping. It’s a 24-hour-a-day job that takes its toll. And it took its toll on me. For much of my career I accepted the challenge, took on board the regular new initiatives, passively resisted the deterioration in status. I continued to “deliver in the classroom”, while taking on ever more responsibilities and developing my career. I was reasonably successful, having reached middle management.

In spite of all the government edicts, target-setting and other arbitrary quality assurances, my own teaching philosophy prevailed - I was there to make a difference. To me, teaching was a vocation, an emotional, caring experience. I led with my heart. I gave praise when due, gave rollickings when I was annoyed. Teaching made me angry, sorry, elated, numb, tense, satisfied - the whole range of emotions.

But, over time, my emotions became more and more exaggerated. I could lose my temper over incidents that, looking back, were trivial, although they never seemed so at the time. I became increasingly restless - every moment I had to be achieving, whether it was marking, preparing lessons, tackling the never-ending stream of bureaucratic tasks or understanding new technology. Relaxation was pushed further and further into the background.

The need to satisfy the demands of my superiors, the Government, school governors, pupils and their parents - and to justify my job to the public - sapped my energy reserves. My family needed me, too. I came last, and when it was time for myself, I had little left. But I told myself (and believed) I was fireproof, I could cope with all the demands. Then, one night, my world fell apart.

I suppose we all have suffered a certain trepidation about Monday mornings on a Sunday evening. I did, but it became extreme and I started using escapist strategies. After planning my working week, I would lock myself away in the kitchen and plan imaginary holidays with the aid of an atlas, roadmaps and holiday advertisements, accompanied by glasses of beer or wine - not too many, but enough to make me feel mellow.

Then, one Saturday morning as I was refereeing a school rugby match, I began to feel as if I was in a different world from everyone else. At the time I put it down to dizziness after running around. But the feeling began to occur more frequently - during assembly, or while I was teaching or walking down the corridor. It became a regular Monday morning experience, as well as at other times during the week. It frightened me while it was happening, but it soon passed. It came and went.

The crunch came, as you might expect, early on a Monday morning. I woke about 4am in a panic. I’d had fearful dreams and found myself wide awake. My stomach was churning, my heart thumping, I was going to die. I believed I had CJD. All the symptoms seemed to fit: nightmares, dizzy spells, problems with balance, involuntary movements, muscle spasms, cold neck and back. I got out of bed and walked the streets for hours, feeling distraught for myself, my wife and my children, who would shortly be left fatherless. Later that morning I tearfully visited the doctor. He told me I was suffering from nerves and prescribed a tranquilliser. Late, I went into work. I confided in a colleague, who said it was probably a virus. The fear and sadness faded during the afternoon and I was relieved to feel normal again. What a prat I’d been, I thought. But it wasn’t a one-off.

Later that year, in August 1998, the worst symptoms returned - the vivid dreams, the waking, panic, dread and fear.

Throughout the following months I was prescribed antidepressants and tranquillisers, but to no avail. And apart from the odd day or two off, I continued to work and attempt to fulfil my teaching duties, although my low energy levels destroyed my enthusiasm and ability to concentrate. Teaching became near impossible, but teachers are martyrs aren’t they? In December 1998 I tried herbal remedies, but without success, and on the first day back at school, in January last year, I took what I thought was the final attempt at a cure - long-term absence, initially for four weeks.

My doctor then signed me off for another four weeks, followed by a further two separate four-week periods, and then for 13 weeks and then a final 13 weeks. In January I thought all it would take was a month or two off work and I would be back to my old self. How wrong I was. My first true acceptance of this was in April, when my counsellor (who had been wonderful) and doctor advised me to think about quitting teaching. I had tried all the solutions - medication, meditation, Tai Chi, herbalism, aromatherapy, hypnotherapy - bar this one.

Throughout the short days of winter and early spring I tried to spend as much time outside as I could. As the weeks passed by the feelings of depression and anxiety gradually faded and the “window of normality” grew slowly but steadily wider.

I knew I would soon be approaching a deadline - I was allowed 100 working days on full pay, then I was on to half pay for 100 working days. For financial reasons I needed to get back to work, but because of the amount of time I’d had off it was up to me to prove to the county’s occupational physician that I was fit to return. I saw him in June - and failed abysmally to convince him that I was fit to go back to teaching in the foreseeable future.

I now risked being sacked, as I was unable to fulfil my contractual obligations and there seemed no chance of my returning to work in the near future. My only option was to seek early medical retirement. I was under no illusions as to how difficult this would be. I’d heard of teachers in terrible physical and mental states being refused ill health retirement by the Teachers’ Pensions Agency. My union warned me that I needed to convince the TPA I was permanently unfit to teach. Any possibility of recovery, any chance of a potential cure, and my request would be refused. So, over the next few months I gathered the evidence I needed.

My counsellor wrote a report on my behalf. In it she said that, in her opinion, I had had years of overload and was burnt out. Any return to teaching would “take me straight back to where I was when I first came off sick”. The county’s occupational physician reported that, despite a long period of absence, medication and counselling, I remained unfit for work of any kind, and that he was uncertain if I would ever be fit to return to teaching.

My GP had referred me to clinical psychology. The psychologist’s report said that if I were ever to return to teaching I would probably return to the old pattern of taking on too much work, which could be detrimental to my health. I sent these reports, along with the necessary standard form, completed by my GP, who wrote that he didn’t think I could fulfil the duties of a teacher for an indefinite period and that a return to teaching might lead to a return of my worst symptoms.

After considering the evidence, the TPA medical team asked me to visit one of their listed psychiatrists. I saw the psychiatrist three times - twice at hospital and once at home. It was his report that proved conclusive. I was consequently granted ill heath retirement in December last year.

The news that my pension application had been granted compensated for much of the pain I had suffered. I am not allowed to teach again - ever. My pension will be withdrawn if I do. I’m satisfied with this situation as I know I could never again take on anything like the required responsibilities. I can no longer bear stressful situations - they bring on anxiety, depression, sleeplessness and nightmares. I am now volatile and unpredictable - I get easily angry and become fearless when I am so.

My memory has suffered and I forget simple, everyday things. I have to be left alone for long periods. For weeks at a time my self-motivation is rock-bottom and I struggle to achieve but a few simple daily tasks. I still get feelings of panic, but usually I can cope with them, often by doing low-intensity tasks - a bit of weeding, a walk around the block, a trip to the shops - consoled by the hope that I should gradually continue to recover. I try to view each day as the first day of a teacher’s summer holiday.

I became a teacher to try to help, to make a difference, to listen, care and guide - a nurseryman and his flowers. But I had become a dinosaur. Teachers are now professional, clinical (and clinically ambitious), unemotional clerical workers - budget managers, number-crunchers, personnel persons. I felt I was one of a dying breed - ideally suited to teaching, but not to the demands of the new teaching profession that has risen from the pile of political interference.

I have not worked since my retirement, although I rarely get bored. I have adapted to operating at a much slower rate. I no longer rush one job to start the next. I go to the gym most days, am a competent gardener, have time for myself and my relatives, and their children. I like to read and learn about simple things.

I don’t know what the future holds for me. With my pension and incapacity benefits I can pay my bills. We can’t afford holidays, changing my car is out of the question and a night out is an hour or two at the local pub. My wife is understanding and accepts our situation. I have no more career ambitions and don’t know if I could ever again hold down a job. Am I angry? On one hand, yes, because my career was ripped apart just when I was reaching that middle-aged comfort zone. I blame myself for this, but I also blame my superiors, who could see what was happening to me but just watched me go down the drain. But on the other hand, I accept my plight and am content with my lot. When you really believe you are going to die in the near future, but survive and can look towards a future again, you are just grateful to be alive and well.

John Mason, 45, is a former head of business and economics at a Nottinghamshire comprehensive.email: johnmason24@hotmail.com