What to do about cheating bf at army boot camp?

we started dating last february. things went great for about two months. then he starts acting weird. before i can go any further i have to explain some things about myself. i am very much a goody goody and physical contact makes me very uncomfortable and it takes me a long time to trust someone to the point that allow or enjoy so much as holding hands. yes i know, i'm weird. anyway, he knew this and would always say it's fine it's fine i won't push you, i know how to wait for a kiss. anyway, a couple months in i'm getting better about the contact thing with hugs and kisses and so on, slowly but surely, but he starts acting weird. i know it's the signs of a break up but i was very unfamiliar with what to do about it and every time i mentioned if something was wrong or was i doing something wrong or what did he want me to do to make him happy he said nothing was wrong, don't worry. there was nothing i could do about it so i let it go but paid attention to the signals he was putting off that things weren't right between us. anyways, before we'd hooked up he'd promised a girl from out of town that he'd go to her prom with her. I was mildly uneasy about it but i told him i didn't care, he should go and have fun with his friends. long story short, the day after that prom he calls me and then has his sister break up with me over the phone... i know, mature right? anyway, i went to his house to see what was up cause i was kind of blindsided with it cause he gave no warning when he called that something was up. we talk, he says he only wants it to be a break until school's out so he can focus on homework. same old excuse, i have too much homework to have a gf right now. anyway, load of poo because i'm one of the top ten in the class of 300 and if anyone understands the need to do homework or could possibly help on homework it would be me. k, so, i'm heartbroken and really pissed at how he handled the whole thing. a few weeks go by and he starts talking to me at lunch, talking to me in the hall, talking to me on msn. i'd already told him it probably wasn't gonna be a let's get back together this summer because he'd hurt me too bad but there he was every day talking to me. i didn't even have to talk back, he'd just sit next to me and talk or try to make jokes. summer rolls around, i tell him flat out that i didn't need him and we should both move on and i think that cut him pretty deep but i wasn't harsh in the way i said i was only honest, cut to the chase. we don't speak to eachother at all for about a month and then out of the blue he calls me up in the middle of june asking if i wanted to come over and watch a movie. as friends... well, by that point i wasn't mad at him and purely because i was bored i said yeah why not. long story short again i'm hanging out at his house pretty much every day for the next month. i viewed him as my best friend but i knew that he wanted to hook back up again. by mid july i finally agreed to give it a try and here i am at the end of september with me at college and my bf at boot camp in georgia. anyway, the point that i've taken so long to get to is that two weeks before he left for boot camp he tells me he's got a confession to make that he has to tell me before he leaves for boot camp. he says that when he went to that prom with his friend he ended up getting totally wasted and basically screwed her all night long. he then told his sister who told the parents who then told him he had to break up with me and figure out if he wanted me or if he wanted free sex cause he sure as hell wasn't getting any from me. what is a girl supposed to say to that? ultimately, i've just buried it and pretended like it never happened and he's sworn to never drink again and never cheat again and never be in a position to cheat again. like i said, i pretended it never happened and we went on with out happy togetherness. but now he's in boot camp and it seems like i'm constantly dwelling on what he did how he treated me and wondering why the hell i'm with him. does he make me happy? yes, very much. but how much of that is reals? does he actually care about me. he trusts me, he gave me the only thing he has from his deceased mother to keep until he's out of boot camp, and i have every valuable possession he has in my possession until he's out but does he actually love me like he claims he does? is he worth giving a chance? what would you do if you were in my situation. and remember, aside from that night, he's never done anything negative toward me and he does make me happy. but how can i really trust him?