I'm sorry, I don't have any advice for you, but I understand how you feel. I'll go to bed very late, not be able to fall asleep, and in an hour, be back on the computer or watching tv or whatever--it gets frustrating, and you get to the point of thinking "why even go to bed?"
With me, it's usually stress, because I am a huge worrywart

I'm interested to hear what your doctor has to say about this.