Do I have an Eating Disorder?

I had a decrease in appetite a few weeks ago, but I have no desire to fix it. I used to eat two or so helping at dinner. I'm skinny (105lbs at 19) but I ate like I should be double my size. I've been eating one meal a day for a while and they haven't been big. But I'm not really hungry anymore. If I'm out somewhere I ignore the hunger until it goes away. I've slimmed down a little, and my boyfriend is a little worried. I just don't feel like eating anymore, I'm never in the mood for it. But I like losing weight. I feel better about myself as I see my thighs and stomach shrink more and more.