Do I have an eating disorder?

First off, let me state that I am not underweight. I'm 5'5, 130 lbs. On the chubby side. For the past year or so, I've been making myself throw up, periodically. I don't necessarily "binge" I just "purge". Early on, I rarely did it, just in times of fat-feeling desperation. That progressed to once or twice a month, to eventually twice a week, and lately I've been throwing up everyday. Sometimes, I'll go a week without puking, and than start up again. As it's not consistent, and I do not "binge", I don't know how to clify or diagnosis this problem. Any advice?