Weight

Hey guys. Background info. I'm 15, almost 16. I'm 5'2. My parents are, well not big, but not small. Ok. Now for what I'm concerned about. I loose weight during the school year, I don't eat breakfast, lunch, and only sometimes I eat a real dinner. My healthy weight is supposed to be like 120-125. I've been drinking shakes packed with proteins. I want to put on a little weight, but deep down I only want to loose more. I'm stuck at 112. I don't know wants up. My ribs show, my wrists are getting thin, my collar bone shows most of the time. But I'm trying to eat more, I feel like I'm eating too much, but in reality I don't eat more than 200 calories in a day. Advice? Please, all my girlfriends compliment me on my great job at staying skinny. But they don't get it, yes I'm happy I'm thin, but it's not healthy, I go days without eating, but not because I want to, becasue I can go a full week or so without getting hungry. Doctors, nurses? Anybody have a reason.