As others have stated, don't underestimate what having too much going on in your life can do to your ability to love and be loved. It's taken a toll on me through the years. So, nothing here new from me, but........
...Do me a favor? Dump her if it's not there. I'm a decade older than you. I dated the woman I'm married to right now, all the way through college, meanwhile playing the field as much as a I could the rest of the time. Not healthy. I attempted to break up with her, mainly so I could play all I wanted to, but it was also unfair for me to do that to her. Now, 12 years later, I am married and less than happy. And her too. If you don't feel it for the chick, let her go. Save yourself a lot of crap many years later on. Breaking up sucks, and I'm not saying it's the answer for you right now. But if it becomes clear that you want to be free, do it. Don't worry too much about the short term pain. It's for long term happiness for both of you.