Have your doctors ruled out bipolar 2 which causes the same type of sleeplessness? As I understand it, it's a milder form of bipolar. Less dramatic cycling. But still the mind cannot shut off for sleep entirely. Still racing a bit.
I don't have it, so don't know a lot about it, but I have a friend who has this version of it, and has alot of sleep issues. I don't know whether she wakes up in the night after falling asleep or just can't fall asleep in the first place. I don't know for sure, but she did say there is a sleep impact from this disease.