I've tried just about everything and still can't sleep. A lot of details inside. Can you give me some advice?

I'm 19 almost 20. I have had trouble sleeping since I was about 11, no idea why. I do occasionally (like 1 night a month) sleep for a full night but not solidly. Every night other than that 1 exception I'm up almost all night only getting up to 3 or 4 restless hours of sleep where I'm waking every few minutes. I'm also Bipolar which doesn't help I know. The medications I'm on are Topamax and Lamictal, neither of which have increased my sleeplessness since I've started them. I do have a high amount of stress due to medical problems such as the Bipolar and Insomnia, also chronic migraines. I also have family issues and work and since I finished High School in May 2007 I'm just now getting ready to go back to school. With all the lack of sleep, I feel dizzy and like I'm going to collapse. I've talked with my doctor and my psychiatrist about the sleeping and we've tried just about everything out there and after no more than a week they stopped working. I've also taken Vicodin after surgeries and that hasn't even knocked me out and that is a powerful narcotic. I have a script for a sleep study but have been trying for almost 2 months just to get someone to pick up the phone in the scheduling department over there. One suspicion was sleep apnea although highly doubted because that is normally found in obese and asthmatic people. I'm 5'5" 125 lbs and athletic.