Its Starting Help Please!!!

Ok so i'm 16, and i've always been uncomfortable with my body image, and have been on/off dieting and excersising semi-regularly for years. I've never lost any significant weight except during my freshman yr, when I went almost semi-annorexic excercised like crazy, hardly ate anything, and lost about 10 lb. However, then summer came along, and I gained it all back+some, and I haven't been able to keep anything like that up since then.I never really did anything unhealthy, but throwing up my food was always in the back of my mind. Then, recently, partly because I think i'm a little depressed, I did it. Not binging and purging, but just sticking my finger down my throat and throwing up w/ e I had eaten. That week I got really obsessive, and hardly ate anything, and threw up what I did. It's not easy for me to make myself throw up either, I don;t have a weak stomach. I really have to make myself retch for a long time. It kinda hurts my throat too. So after about a week, I started to really freak myself out, and was like i'm stopping this, w/e i'm not fat, I can eat w/e I want. So I basically went it the oppisate direction for about a week. The tonight, I got in a huge fight with my parents, started feeling really bad, (and fat, that was on my mind before anyways), and I threw up again. Unfortunatly, it felt pretty good. I'm not so sure I have so much control anymore, and am really worried i'm becoming belimic, which is a problem I really don't need, but I don't want to feel fat anymore either! Please help!!