I'm empathize with you. I didn't see 'reading' on your list of things you've tried doing to fall asleep. In the past, I could never fall asleep unless I was reading in bed. my insomnia became even worse because of more life stress, so for days, I was reading for many hours before I could finally fall asleep. One night, I finished my book and needed another. All I had left in the house was the great dialogues of plato. I was so bummed, but I started to read it, and was asleep within minutes. Every night after that I would read that book, and never make it more than ten minutes before I was sleeping. after a couple weeks I could read my normal stuff again and fall asleep.
So, maybe it will work for you....find a book you think is really boring and force yourself to read it; focus your attention on it and hopefully before you know it you can get some sleep.