Am i weird about love?

Ok. Im not like all the other guys. I don't go out with people for the bloody hell of it. I am in highschool, and i've noticed nothing lasts. I really love this girl, and she likes me back. This isn't a little crush. Its big. I don't want to aks her out in the fear of losing her because we break up in 2 weeks. I am really serious about this girl. But i think if i leave it too long, she wont like me anymore. What should i do?