Bobby's got it all worked out!
WestVirginia, you can't have love without trust. I know it is normal to be jealous sometimes (I sometimes am, and so is my boyfriend [and we are also long-distance right now]), but you have to know that, if he is a good guy, he wouldn't be in a six-hours-away relationship unless he really wanted to be with you. If you are sure that he's a good guy who loves you, you need to trust that he'll stay faithful to you.
Also, if you are jealous of little things like girls signing his facebook (sidetrack: how many guys sign yours?), you would probably still be madly jealous when he returns (ie, if a girl asks to get lunch with him, study with him, calls to ask what day the exam is, etc.) even if he does show you he loves you by getting you a card (a la Horatio) or chocolates or whatever.
Bottom line - you're hurting more than just your relationship. You're hurting him and even yourself by not allowing yourself learn to trust. That can potentially kill a relationship.
A little counseling wouldn't be a bad idea... or at least talking this over with friends. If I were you, I'd apologize (call or maybe write a letter) for being jealous and make an effort to start curbing the jealousy. Easier said than done, but you have to start somewhere. You're going to have to trust him, or the relationship will go nowhere. You're going to have to trust someone, or you will never trust any future boyfriends.
PS - I'm sorry to hear about your ex-boyfriend and best "friend". That's a really awful and revolting thing to happen.
