I used to be on 300mg Lamictal and there was a time I had problems with sleep. I would be tired and would fall asleep after about an hour but I would wake up and stay awake a few hours later.

I tried Seroquel at 25mg an hour before going to bed for a few months and it worked. I was able to stay asleep. I stopped it after a few months because I found I was able to stay asleep again on my own.

I used to take Lamictal at night though since it made me really dizzy after I took it but it was ok by the morning.

I hope things improve for you.