I think I have an eating disorder... is it one?

Well I can never eat. The less I eat, the better I feel. I'm about 5'8", 120 pounds, && I'm not THAT skinny, but I can't eat without getting seriously sick, with either puking (which is rare but it does happen) or getting migranes. But every once in a while, I'll be STARVING && eat a bunch of food without getting sick. I've already dealt with anorexia a few years ago && I was treated again for malnutrition a few months ago... so what should I do? I honestly don't know what's wrong with me... but the headaches are the worst pains I've ever felt, && I just want to know what I can do to make them stop. I don't have many body issues... I just wish I was a bit skinnier, but otherwise I have pretty high confidence.