I can't let go of this girl. It's driving me insane

I'm 18 years old and I party a lot. A lot of the parties I'm going to, this special girl is here, and even though she is in a relationship with one of my best friends I can't forget about her, and I wanna pursue her so bad. How do I forget about her? I really dont wanna hurt my friend or seem awkward, but this girl is just perfect to me.

We havent kissed or anything, only talked so nothing is pointing at her really liking me, but to me she is just perfect, her smile, her humor, her face.

I can't enjoy being drunk, since all I can think about is this girl and how to handle this situation. Yes I am drunk right now, and it bothers me that I'm not able to enjoy it.