RELATIONSHIP NIGHTMARES...PLEASE HELP!!!?

There is this girl that I was always in to. She is kind, beautiful, but most importantly intelligent. We were great friends in high school and then went to separate colleges, but still remained good friends who kept in contact once in a while. I always thought that there could be something there, but I never went for it. Mainly for two reasons. One, I was always concerned what would happen if she turned me down. But most importantly, there was a chance she didn't think of us in a relationship, and I didn't want to ruin our friendship or make it strained or awkward. Like I said, we are still good friends to this day (both still in college) but I have found myself still wanting in a relationship with her. I think she is perfect for me and as a result I can't move on. I think she may be "talking" to some guy that she goes to school with, so that is unfortunate, but I'm not sure. It's just hard because morally, mentally, and physically she is what I want, but I don't think I can have. But like I said, I can't move on with someone else because I find her to be perfect. What should I do?