I wish I had some advice for you also, my difficult child can stay up till midnight and still will wake up around 3am, luckily at that time I can usually get him back to sleep. although it usually means he sleeps in husband's and my bed and I sleep downstairs.. (can't fight that early in the morning.. lol) But even after that he will be back up between 6 and 7am on weekends, during school week he's up at 6am (bus arrives at 6:30). psychiatrist even increased his Trazodone to no avail, he's also been on Remeron.
My thoughts are with you and I hope you find something that helps soon. ~sending hugs your way~