Have you tried going to sleep earlier? Sometimes that is all it takes. I know you said you don't feel tired at night, but if you lay down early and just turn off the light and try to go to sleep, it might help.

Also, there are some OTC sleep aids you could try. Melatonin works for some people, although it can make you have some weird dreams, it did for me. Also, just regular sleeping pills can help, at least until you get on a more regular sleep cycle.

For me, it helps that I take 200mg of Seroquel at night, about an hour before bed. You could talk to your pdoc about it and they might be able to prescribe something.

Overall, though, I think it comes down to retraining your body to sleep on a more regular schedule.