Bulimia or not? Tell or don't tell?

okay, here's the deal. I have been throwing up my food deliberately, since last month, when I threw up at school accidentally because I got in trouble. I don't usually get in trouble, so when I do, my stomache starts twisting. So I went to the bathroom and puked. My friends were with me and they took me to the office to go home. I didn't want to cuz I didn't feel sick, but I went home anyways. Since then, because I noticed that barfing wasn't so bad (didn't hurt), I threw up my food again, and again and again. I thought I was fat for over 2 years now, and last year, almost all the kids at school thought I was anorexic cuz I was eating less. So now I'm stuck puking out everything I eat and I want to stop but I can't. I'm not sure if I'm bulimic or not cuz I only throw up like, 3-5 times a week. I don't want anybody at home to find out, and I know that if I tell my friends, they are going to tell a teacher who will tell someone at home. I try to avoid puking at home, so I do it at school