How does one get over a serious relationship?

My boyfriend of about a year just dumped me, and I'm torn up about it. I was so in love. Still am kind of. And I don't know how to let go. I just moved to college, and I want to start dating again, but everything reminds me of him. And every time i think of him, I either want to cry or throw up. Or both. Basically, what I need are tips on how to move on. Also, how do I learn to trust again? I keep trusting people, and they keep losing interest in me and hurting me.