Relapsing

A year and a half ago, I began starving myself for reasons I can no longer remember or rationalize. That time of my life is a blur that I don't want to try to clear up right now. Around this time last year, I got really sick and lost my appetite for almost a week. I could barely eat and lost a lot of weight. Not long after that, I went through a really stressful time and couldn't gain that weight back, even when I tried. I was outwardly distressed at my skeletal appearance, but inside, I was overjoyed. There was a part of me who was delighted at finally being skinny.
Somehow, though, my stress habits changed. Instead of not being able to eat or losing weight when I was stressed, I began eating constantly. I quickly began to gain weight and even almost didn't fit into my prom dress. It was nice to not be asked if I was sick as much, and I even resolved to start exercising so I could continue eating but also keep a decent figure but...it's october, and that didn't work.
The fact is, I want to starve myself again and I know part of it is just the disgust at what I've become, but there are other reasons that make no sense to me. I'm upset because my boyfriend wanted to break up and even though we're fixing things, that involves not talking as frequently, which sends me into bouts of depression whenever he doesn't want to talk to me. He's my only real friend, so he's the only person I have to talk to. i'm also stressed financially because I have a big trip coming up, my last one in my choir, so I have to go, but I haven't been able to find a job and there's no way my family can afford it. Finally, i'm stressed about college because my grades took a complete nosedive my sophomore year when my depression got really bad and they never picked up, so I probably won't be accepted to the only school I'm able to go to (location + tuition paid), but even if I am accepted, I'll still feel stressed about going to college at all. So, for some idiotic reason that is entirely beyond me, I feel like starving myself and getting really skinny again will solve all these problems, even though I know it won't/
I just don't know what to do right now...

Good for you for staying out of denial... it takes a lot of courage to be honest with yourself. Don't let anyone tell you that this isn't a real problem because that is a lie. It sounds to me like you feel like you don't have control over most of the areas in your life. For most of us, I think, our relationship with food is one thing we CAN control, so our minds focus obsessively on it and it becomes our world. My advice to you would be to try and find something more productive that gives you a feeling of control, and it might be good to talk to a professional about what you are going through. You are at a crossroads. You know that relapsing will not be good for you physically or mentally. Please try as hard as you can to have faith in your ability to break this pattern before it breaks you. It's not easy, and you can't expect anything to change overnight, but as long as you keep fighting, you can do it, and you will be stronger because of what you are going through.