I find it hard to work and hold down a job

I studied counselling at college and graduated, but found it very hard wo work and even get through a full day's work there. I would get tired, get so nervous talking to people and when the phone rang I would jump. I also found it hard to process information and to remember little things and to speak to people. I finished that job before I got fired. Then I took on a job as a nurse, I still got nervous and made the patient's nervous and left that job before something serious happened. I also got a job in an office, a factory. I forgot little things and almost lost my finger at work and the people in the office said I was slack because I found it hard to take initiative and be a self directed employee. People say I am dumb and I am lazy and stupid. I took a job in a box factory and my hand shaked so much that I could not put boxes together and people yelled at me and the weight I gained made it hard to move around quickly. I am taking a break and trying to gain self employment, possibly as a writer. Does anyone else feel this way? I know I have done remarkably well and some people never come as far as I have. I have overcome the worst and realise I have come a long way. Nobody in my life now even realises there is anything wrong with me. My doctor said he does not know anyone with my disease who has come as far as me. I know I should be proud of myself but people who don't know I have it think I am slow and backward. All these thoughts roll around in my head and it is hard to sort them out. I do lots of exercise to escape the anger, and am losing weight I gained because of it. I have to work harder than others to lose weight but am doing it. Please help.