whoa ! what's the big deal, buddy. first off, it sounds like you want to be a hell of a lot more than just friends with her.
if you really look at it, it's just some random girl you met before college even started- imagine how many more there'll be when it DOES start. did she have a halo over her head? a tatoo with your name and birthdate? alyssa milano's sluttier twin sister? don't let it bug you so much. bermuDa's right, this is far from something to get depressed over. seriously, you had an encounter with like one of a billion fishes in the sea (sounds like you go to a big college, too!).
you'll probably see her around campus, but if you don't, no big deal, right? it's a surprisingly small world, you'll probably meet her at a party or at least someone from the same dorm that knows her. anyway, you just learned one of the most valuable lessons of college right off- ALWAYS carry a pen with you.