Do i have stomach ulcers from throwing up randomly.. a LOT?

Ever since my girlfriend of 6 months n i broke up every once and a while the last month or two i will randomly throw up. i feel kind of depresseed but not all the time. I feel like i have a knot in my stomach a lot. Im in pretty good shape and eat right. But ill randomly be with friends at the mall and i started barfing everywhere. Thats happened 3 or 4 times now. Do i have an ulcer or is throwing up being depressed or what? any opinions appreciated.