I think I called this in the thread you posted about her. I hate to say I told you so; but I did!
In short; here's why it will fail.
1. She has NO IDEA where she's going or what she wants. She's too young.
2. She's in an environment that you aren't.
3. She's surrounded by nothing but influences that will suck her into behavior you don't want her in.
4. You've given her pretty much everything; so why would she not scope out some fresh?
5. Girls in college act like guys in college; what did you do in college?
6. She's cut you off emotionally and she's not going to let you back in. It just doesn't happen like that.
Cut her loose; and do it in a way that she knows you're the one doing it; not her. Let her get fvcked and chucked by a couple of guys and see what it's really about. Do not hang around as a friend.
It sucks to be in this spot; but from what it sounds like; you'll have an easy time finding someone else no problem.