[K. in Cleveland]

I agree with D&J. I can also say, in my experience, usually the partner who freaks out the most at any possible signs on infidelity, or who accuses the other of cheating, is usually hiding a guilty conscience. This is actually human psychology at it's best. If I blame you for what I'm doing, you'll feel bad and won't accuse me of doing it. Now, I don't want to say that Jessica was cheating on you before you broke up, I don't know her. I'm just saying that this has been my experience.
But I definitely would try to move on. It sounds like you are quite young (speaking about Spring break) and believe me, relationships like this come and go. And yes, the rollercoaster relationships are the hardest to get over. It's more of a law of chemical than romance in this case. You get hooked on the adrenaline and other fun neurotransmitters that one of these relationships causes, and in turn, it is interpreted as inflated feelings for the partner.
(OK, so maybe I enjoy studying psychology, sorry if I got a little technical)

I hope you can get over Jessica and eventually move on to a more even, emotionally stable relationship. Oh, and this part kinda sucks, but usually it is best to make a clean break and not try to be friends. Being friends after a relationship breakup tends to lead back to the merry-go-round ride of on again/off again relationships.

Hope this helps,
K. in Cleveland