you have no business being in a commited relationship at your age. you are still in college. have fun and date around. you should be dating 3 or 4 chicks at one time in your spare time and focusing on finishing your education.
once you establish yourself in life and save up money, have a house, and a career/business in your 30's or 40's you can worry about getting married.. in 10 years you will look back and laugh at yourself for crying over this slut and wonder how you could of ever dated her in the first place. i guarantee she will have 3 kids by 3 different fathers..