Am I anorexic or is there something wrong with me?

Am I anorexic? I mean this could be a stupid question, but I eat only when I feel I have to. Sometimes not everyday. But I'm not doing it to lose weight. I'm just not hungry. Sometimes I have to force myself to eat because my body feels weak. And I know that I need more nutrients in my body. I take women's 1 a day, but I know that this isn't enough. What can I do? I don't force myself to throw up but when I eat to much, my stomach hurts so badly that I want to throw up. But I suck it up and keep it down. Or I'll take some pepto. Like I said, I'm not doing it to lose weight. I just can't eat regularly like everyone else. Can anyone help me? I'm at a dead end and I don't know what to do. What is wrong with me?