Ummmm your gf definetely should leave you if you refuse to put any attention on her. I mean do you seriously expect any girl to go out with a guy who's schedule is completely packed and won't give up any of their time to her? No, they won't. So i suggest...
1. Either admit to yourself with your lifestyle you will never have a gf.
2. Change your commitments to get a gf if you want one.