She got what she wanted from you, you got her through school. That is like a classic dump story, the only difference is that she doesn't have the great future while you took dead end jobs to put her through school.
The real question is how do you feel about her. Is she the one? Does she make your heart skip a beat when you think about her? Do you rush home to see her (granted right now with her stuff that might not be practical)? If you feel that way about her, then do the things that you need to do to win her back.
If you don't feel that way, then run, don't walk to the nearest exit, and face it, she used you, and you used her, but now's the time to call it a day, before you have children and there's no way out because neither of you feel it, but you're staying together for the kids.
I saw the writing on the wall, but refused to read it, and my dear former spouse at least had the gumption to call it day after three kids. It wasn't nice for them at times, but we've all gotten through it, but my children would have been much better off had they been born to a mother who knew how to be a mother, and had a nuclear family that didn't go nuclear every so often.
Good luck.