I Think I'm in Love with a girl who lives far away?

i have grown up with this girl since i was like 3. i am now 14 and she is 15. when we were 9, she moved to virginia. i live in ohio. we still keep in touch and she comes to ohio once every month or two. i just recently realized how i felt about her. when we are together i feel amazing. i would actually rather sit on my bed with her in my arms than do sexual things. now don't get me wrong,we have done some sexual things, but just being with her makes me happy...so anyway, she came back for a week. she just left yesterday, and i found myself crying. WTF! i never cry, so it took me by suprise. right before she left she told me she loved me and that someday we would be together when we both got out of school. i consider her my best friend and she thinks of me as the same. i have no idea what to do...