Why can't she just love me back?

I've been hopelessly in love with one of my good friends for a few years and its really killing me. I've told her that i liked her when i thought the moment was right, but it just made things awkward. Now it seems she doesn't trust me as much as she used to. I'm in highschool and since its full of cliques i don't think i'm popular enough to go after someone as popular as her. Even though she invited me to the sadie hawkins dance a few months ago i still don't feel good enough. We're both shy so i always have to try to make the first move and whenever i ask her to hang out its kind of like a suggestion but we never actually do. We can text each other for hours and it seems like she's really into me, but i know she thinks we're too good of friends, What should i do? Should i just give up or am i doing something wrong?