Here's the deal. Been with my current gf for over 6 months, I love her, she's an incredible human being. But females are going to be females so...

We both are in college. She lives in the state over and goes to school there while living with her father, but only about 1/1.5 hours away by car so not that far at all. We are both very busy people and I am in a very demanding major with a suite of hobbies on the side, but we make it work. We try to see each other 2-4 times a month, which works out fairly nicely. She always comes to me for the most part, except when school isn't in session we go back to our similar hometown. I'd obviously like to see her more, but seeing her in doses does have its virtues and I'm the type of person to need lots of independence and space anyway.

But I think the distance between us and the frequency that we see each other is straining us a bit. She is constantly complaining to me that I put in no effort to see her, I never go and visit her, etc. which in a way is true but I have my reasons for it (not trying to deal with her dad because she lives with him and I wouldn't be able to sleep over complete waste of time and money to go there) There are things she doesn't do enough of that'd I'd like more too (sexual things, etc.) and I don't make it a big deal about it.

How should I respond to her? She has said to me that I think my time is more valuable than hers, which to be honest, isn't false. I told her to stop bitching at me and that I'm not in the mood. Any additional pointers?