moving on

Sorry for how long this is going to be...it's hard to explain in short.
So, there's this girl that is pretty much my best friend and I still have strong feelings for her. I told her I was bi about two years ago, and she was cool with that so then I few weeks later I told her I liked her. And thinking she was straight, I didn't really think anything would happen. Shortly after that she told me she liked me too, which was a real surprise. So then a couple months later, we ended up making out and stuff when we were drunk and she initiated it all. She then freaked out about the whole thing and didn't talk to me for about 3 months...then she apologized and the same thing happened again; we got drunk and hooked up. She claimed this was just because she was drunk and I was the only girl she felt this for. So whatever, I figured that's just the way it was. That was in June 2007, and since then whenever we drank together she would try to hold my hand and stroke me and stuff. This past summer she became good friends with a girl who is a lesbian and they ended up kissing and have now been in a relationship for over 6 months, and it is getting really serious. I guess this is the hardest part, because I had figured she didn't want to be with me because she just wasn't into girls. But now she's only into girls...so I feel like I wasted my chance. We are still really close and when she is telling me about my girlfriend it makes me feel so sad and jealous..ugh
So pretty much, I still kinda think I am in love with her and I don't know what to do. I know nothing is going to come from it and I try not to think about her but I always do. I can't handle it anymore.
Any advice?