I don't know what to do. I am a male senior in high school and I like this one other senior girl. I have never felt like this for any other girl. The thing is she has a boyfriend but I don't think he is in this country.

We don't have many days left in school. I am nervous to talk to her so I barely interact with her. I have opportunities but I don't take advantage of them. We make a lot of random eye contact throughout the day which makes me even more delusional.
I am tossing and turning for 3 hours when I try to sleep for the past 4 days just thinking about her. Should I try talking to her or not try at all?
I was thinking of asking her to prom, but I don't know if I am close enough with her to ask that.