I'm a senior in high school, with only a couple weeks left, and I've had strong feelings for this girl for about 5 years now. We used to be friends, not best friends, but friends, and over a summer's time and my feelings for her getting stronger I grew too shy, too uncertain, afraid of rejection, afraid of hurting her, the leap into high school, etc, and stopped talking to her. She knew for a while (when I still talked to her) that I had feelings for her and we grew close enough that I could tell she had feelings for me before that summer. We emailed still for a while and she even asked me why I didn't talk to her, a question I couldn't answer, and I do see that I could have asked her the very same thing, but I know she's also someone who waits for the guy to make the first move. For a couple years actually she gave such obvious signals that she wanted me to talk to her and probably just wanted me, but then that pretty much turned into a cold shoulder making it beyond obvious that I hurt her pretty bad. Toward the beginning of this year I sent her flowers and wrote her telling her she meant the world to me and I wanted to trying being friends with her again before that moment seeing her frequently could become the moment I never see her again and didn't want to regret my indecision forever; I saw her a few days later and could tell she'd like that--I still haven't and that was maybe seven months ago. I also learned from a mutual friend (completely another story) that she doesn't understand why I don't talk to her. Knowing that probably makes it look really bad on my part and may show that I don't deserve her if I can't/won't even do anything about that. The thing is she now has a boyfriend (that goes to another school) and that moment all my chances vanish is less than a month a way.
I don't want to get in the way of her and her boyfriend because I want her to be happy (if she is), though, at the same time I don't want to regret saying nothing and really think she should hear my feelings coming from me verbally. Plus, the way I feel now is that if I don't I'm probably going to destroy my own heart, so... How should I approach her? What do I say to her, knowing that no matter when it'll have to be around her friends? I only have two weeks w/ few chance encounters, the senior breakfast/signing party/graduation rehearsal, possibly a few moments at graduation, and the all-night senior party after graduation.