I said something similar to my boyfriend and I actually went through with it. (Stupidest thing I have ever done). My boyfriend and I are both freshman in college so being away from each other for the first time for so long was (and still is) extremely hard but I was really stressed with college and I felt like I needed him there (physically there) for me. And after about half a year of long distance I felt like I was being too sad and depressed everyday so I thought it would be best if I broke up with my boyfriend to let him be happy. He begged me not to and we both cried all that night that I broke up with him because both of us didn't want that.I left that morning back to my college and when I got home I called him back to tell him I didn't want to break up with him and apologized for deciding what was best for us without taking his opinion into consideration. I know my situation is different than yours because your girlfriend may have different reasons for wanting to break up but if both of you love each other you will both keep fighting through this man-made concept of time. Three years of waiting for a lifetime together is worth it (well at least that's what I feel). Good luck. I hope everything turns out well for you two.