Could I have an eating disorder even though I'm not super skinny?

During the week I eat one meal a day, dinner, because I dont want my parents to notice my lack of eating. I dont eat breakfast and I dont eat at school. I count calories CONSTANTLY, and if I eat something I know I shouldnt have eaten, Its on my mind alllll day long. I feel super guilty, and it gives me more motivation to eat less. I havent had any dramatic weight loss because im so up and down with the consistency of this. but, like I said, if I cheat.. it consumes my conscience. Ive noticed a little weight loss, nothing too drastic. I want more. This morning I had an iced capp from Tim Hortons at about 11. I havent eaten since, and dont plan on eating until dinner. Most days I wouldnt even have an iced capp. I consider that a little weekend treat. So what I want to know is, even though Im kind of yo-yo ish about my eating habits and not SUPER skinny (but want to be), do I have an eating disorder?:/