Have you tried meditation? When I do it, I tend to get through most of that nonsense a lot faster. Just sit, focus on breathing, and if something pops into your head, recognize it and clear your mind. Eventually things should settle down and you can try sleeping.
Set an alarm for 10-15 min. Sitting on the floor is best, but aid that's uncomfortable, a chair is fine for the first few sessions to see if it'll work.