I used to be like this in graduate school. I started working out more and more, treated with sleeping pills and now I sleep regularly between 10pm-2am and I'm up 6am-10am. If I have meetings, sometimes I cope on 6 hours of sleep. Have you tried really, truly beating your body into exhaustion after work 1-3 hours at a gym? Incidentally, that will help the gf problem as well (:

Otherwise, there are plenty of jobs that will let you have a bit of a flexible schedule if you want. Many startups will let you work the hours you want if you are hugely productive.