rebound

Well here's my story:

I fell inlove with my friend (who's a girl) and I asked her if I could court her, but she said no. But we still maitained a relationship as a friend. Then she met this guy online and started to spend more time with him than me and it made me feel miserable because i felt like I'm only an option to her (not only in this incident that I felt like an option to her, but also in some incident that I kept remembering). And here's my problems

1.) Should I leave her? I don't want to say goodbye because I know she will only stop me even if she doen't mean it.

2.) I'm having this urges to be in a relationship again. Should I go for it or what?

You can't really be friends with a girl you want to date. If she isn't interested in dating you, then I would consider cutting ties. To maintain this pseudo-friendship is to rub salt in your wound.