Jaded, I used to have trouble sleeping when they switched me off of Seroquel. It is VERY frustrating. I would try to do some different things and try to sleep. When you are worried and you "try" to sleep it makes matters worst.

1. do not eat anything heavy before going to bed
2. only use your bed for sleeping or intimacy - otherwise you'll be ok with paying bills etc and your mind will wonder to those things when you try to sleep.
3. have some sort of white noise in the room. They sell the actual white noise machine but anything like a loud fan would work. (this decreases the annoying sounds that you might focus on instead of sleep like husband snoring, leaky faucet)
4. about 20-30 min before bedtime take time to let out all worries. Write a to do list or talk to someone about your concerns etc and get it out of your chest. This will help clear your mind. (yea, I know ... I never had my mind be quiet ... but it does minimize the thoughts)
5. make sure the room is not too hot. it should be about 68-70 degrees for comfortable sleep.
6. make sure the room is not too bright - when you turn off the light and your vision adjusts, you should only be able to make out the shape of your hand.
7. last but not least do not do anything that will keep your mind too busy before going to bed - no tv, or books, etc - keep it simple and mindless.

I really hope this helps you. It helped me when I went through it and although it was not a full night's sleep, it was better than no sleep at all.