If I wrote of all the symptoms that I experienced everyday, you wouldn't believe me. Apart from being physically exhausted, you also have "brainfog" which is where nothing is in your mind because you don't have the energy to think – to the point where you can't string two words together. You're so exhausted you have constant body pains, not like muscle ache, more like muscle pain everywhere. You have stomach cramps every time you eat and sometimes you can't physically put food in your mouth because you're exhausted.

When I was first diagnosed my hands were so painful my family couldn't touch them and I had unbelievable headaches, so bad I wanted to die. Nothing helped, I didn't have a single moment of relief. Sometimes you cannot even sleep because it's too painful to put your head down. On top of that, you also experience uncontrollable sweating, even though you aren't doing anything. You are sensitive to light and noise. You can't focus on the television because of the bright lights and you have no strength to follow a programme. You don't have the energy to talk and there is insomnia as well. You can have all of these symptoms together at the same time, all day and all night.

This is what it is like having ME (myalgic encephalomyelitis), often referred to as chronic fatigue syndrome or post-viral fatigue syndrome – and also known as "yuppie flu". It is estimated that 250,000 people in Britain are affected by the illness, which is difficult to diagnose because there is no known cause. This means there is no text book way to treat it.

I was diagnosed with ME when I was 14, after every other possible condition was ruled out. I had had doctors telling me to go to school because I didn't have a temperature. They would look at me like I was faking the symptoms to get a day off school. But I was lucky enough to have one doctor who knew what she was doing. She got me an appointment with the local paediatric doctor because I had been back every two weeks during a six-month period.

My life changed the minute I walked into the hospital room of that paediatric doctor. I knew it was serious and I felt completely in the dark, as if everyone around me knew something I didn't. I had vial after vial of blood taken to eliminate every other potential illness. When he said you have myalgic encephalomyelitis, I knew it was pretty serious. He also said that little was known about the illness or why we contract it and that made me feel utterly isolated. I felt like I was the only person in the world and everyone around me had dropped off.

Coping wasn't an option. I completely blanked it out, believing I was going to be fine. I was in denial. Everyone around me was ringing up charities for support, cutting out every piece of information they found and I felt like ME had me, not the other way around.

While the family were stressed with trying to get me education at home or trying their hardest for me to become "pen friends" with someone else that had it, I felt alone. It was very surreal, as though I wasn't really there. I was just a walking bag of symptoms.

ME grabs you in a way that you are not prepared for, you and your family. I felt like I was being made to feel ill, made to stop school, made to stay in bed. I felt as though I wanted to slip away and never be found.

Leaflets tell those with ME to feel a certain way and you feel restricted and compelled to feel like that, as if it's expected. For the five years I was constricted to the sofa I didn't live, didn't hope or feel happy in myself which is a desperate thing. I didn't want to talk about it, hear about it, or say: 'I have ME'. There is something shameful attached to it.

I was the only one in my school to have ME and I felt as if my had friends disowned me, so I stopped going and was home tutored. They tried to stay in contact but I remember one specific time when I knew I wasn't like them any more. We went to the cinema and my friends were all chatting about school and I had nothing to say, I felt completely disconnected from them. They weren't part of my world anymore. They tried to understand but they just thought: 'She's tired and she'll be back at school next term'. But next term came around and I wasn't there.

I became trapped in time by the illness. I had to grow up mentally but I was constantly around my parents (who were my carers) so all the teenage things, such as reading magazines and finding your identity, became consumed by their grown-up ways.

Someone with ME can be feeling like they have been hit by a truck and yet it doesn't show, because you look completely normal; you don't have a sign over your head saying: 'Girl with ME'. Maybe that's a curse, not to have our illness defined in a certain physical way, such as cancer patients who undergo chemotherapy.

I really didn't like it when people who did not know the extent of my ME would presume I was lazy and sitting on my bum all day. Someone would ask what I had done and I would honestly say, 'not too much, just resting', and people would look at me as if to say: 'You can't have just done nothing?' But truth is, when you are that ill you can't do anything at all.

ME needs to be taken more seriously, so the sufferers do not feel the need to hide the way they do, so they can tell people how horrifically ill they feel. The latter rarely happens as patients don't tend to tell others how it really feels. People that label ME as simply stress or "yuppie flu" are narrow-minded and don't deserve to know the brave people who have it. People like that, including doctors, need to be brought into the 21st century.

When I was 18 I went to a clinic and saw a psychologist every two weeks for two years. I can't describe all the heartache it takes to get better. It happens so slowly and in a way I didn't feel better or notice I was improving until I did something major, such starting college, taking driving lessons or swimming 18 lengths twice a week.

Getting better takes patience. You have to accept it is going to take a long time and to be prepared to take baby steps as you rebuild all the muscles that have been going to mush for five years. Even to this day I have headaches, but they are not even a smidgen on the ones I used to endure. I still have aches and pains and fatigue, I still have to (and will always have to) take care of my body and pace myself with new things.

I need to recognise all the things that make my ME worse. The one thing that makes me certain I am better than I was, is that I can do a whole month's food shop with my mum and it's the highlight of my month just because I simply can.

I feel inspired by having ME. I feel inspired to live every day the way I want to, as there were so many days I couldn't. I have the determination to look after myself and not take my body for granted and I have promised to myself to do all things I wanted to and, more importantly, all the things I had ever dreamed of doing.

• Rose Perkins is a pseudonym.