No offense, but if u don't know what to talk about then i think the problem is within you. u might need a good counseling from a pshychiatrist, and by saying so i'm not trying to offend you and i'm also not saying that you are insane. it just means that sometimes situations arises, things happen and you might seek a counselor, since a psychiatrist is a professional in this regard, may be a good choice for you.
If you are still in college, you might get some counseling at the counseling center on campus. i think you need to sort out the relationship matters ASAP, else you may develop mental depressions and so on.
Gather all your courage in you and talk to her immediately and try to be very open. hopefully u can reach to a conclusion soon..
& remember getting rid of something doesnot necessarily solve a problem. you need to be able to tackle and fix the problem, not just give up! breaking a relation would give u a relief for now, but might affect u and ur partner mentally in the long run.. so think carefully!   
at last: "वार्ता बाटै सबै कुरो समाधान गर्नु पर्छ ।"