dude your problem sounds very similar to the one I had in high school. It was actually almost the same situation really. We were good friends, nothing more, then she said there might be something more. Instead of making a move, I sat back. Now she's got someone else and we barely talk anymore. Dont miss out or you might spend the rest of your life wondering what if??

...we also got drunk together one night, then she jumped on me and we went at it, yet still nothing now...DO IT.