Why am I so sensitive?

I get very irritated by my sensitivity. I am physically sick when I’m stressed over things. I’ve met other people that don’t have to deal with that happening to them. Why do I have to be one of the sensitive ones? I have got ill due to things that have happened and in my eyes this makes me some kind of weakling. I don’t want to be affected so badly but that is how stress and constant anxiety affects me. I know that I haven’t helped the situation by abusing painkillers but originally I took them for intense migraines. That was a reaction to stress too. I get migraines before I’m sick. I keep feeling dizzy regularly but that could also be anemia again. I know that I shouldn’t have missed my blood test but I was too exhausted to get up. It’s like fighting a weight in top of me when I get to that point. I have had enough of feeling ill. It’s constantly every day now. I never get a break from feeling crap.