Try and set a "sleep routine". Even if you don't get to sleep until say 4am still set your alarm for whatever time you want to regularly get up. It will suck for a few days but it will help you regulate your body clock. Make sure you dont sit on your bed and work or watch TV, only use your bed for sleeping. Turn off TV/phones/electronics about an hour or so before bed. Have a routine to settle down so have a shower or bath, put on some cosy PJs, have a warm milky drink, read a book then go to bed. If you can't sleep after an hour or so get up and wander around and do something then try and go back to sleep after that. Don't eat a heavy meal too close to your "bed time". Practice mindfullness before bedtime, there are some good guided relaxation exercises you can do. Do your excercise in the evening rather than morning to tire yourself out - it makes you feel more awake at first then tires you out. You are best doing it so that you finish your run or work out about 2/3 hours before you want to sleep then afterwards do your wind down like i said above. Keep going with all this don't just give up after a few days.