My 'Eating Disorder.'

To start this off, I'm just going to say that I don't eat lunch at school.
Well, one day I was sitting at the lunch tabel just talking to my friends or whatever and one of the guys that sit there was like 'Why don't you eat lunch? You're anerexic.' and I said 'No im not, I just don't like the school lunch.' [Which I really don't like it.] But then his friend said 'Nah, She aint anerexic, she's to fat to be.' And all the guys, and even some of my friends started laughing. Now, i'm not some physco person like that one dude off of Degrassi, who gets joked on and goes and shoot's everyone. Im not like that. I know i'm not the prettiest girl in the world, But I know that i'm pretty, and i'm smart, and I have a lot of friends. But anyways. My eye's started watering up, and I went to go ask the teacher if I could leave the lunch room, and go to the bathroom. She said yes. So I went in the bathroom, and made sure nobody was in there, and pulled up my shirt and started looking at my stomach. Well it was about 5 seconds after that a person came in and I walked out. Well I knew I could get through another hour of school.. So I just stuck it out. When I got home, nobody was home so I went and put on my soffee shorts and a T. I lifted up my shirt once more, and looked at my stomach and started looking at my thighs and everything. I got upset that I went and ate a whole bunch of stuff. A lot of junk food, chips, and everything! Then I went back in my mirror to look, and I started crying again. I felt bloaded as hell. So I went in the bathroom, and stuck my toothbrush down my throat 20 minutes later, and started throwing up. After 100 purges, I was 100% sure everything was out. I felt better. But I felt bad because I was doing this to my body. So I went and started cutting myself. But anyways. I kept eating as much as I could, and then I would throw it up that day. And the next day. And now, my stomach is on its own cycle. Every 20 minutes, after I eat something, It gets thrown up on its own. I use to be 120 lbs. Now im 90 something pounds. I'm not sure if I want to stop doing this..But I dont want to die of this either. All im looking for, Is help. I keep asking and asking, and heartsupport is the only thing I have.