I'm so sorry you're having this problem. I have difficulty sleeping because of a hyperthyroid. Reading puts me to sleep. Unfortunately, It doesn't keep me asleep. But I do find that if the room is cold and very dark, I sleep better. I've also found that a lot of physical activity during the day sometimes helps me sleep at night. When I was in chemo and couldn't sleep due to the steroids, the nurses used to tell me to take a Benadryl, but I just read Cheryl's post, so I guess you need to make your own judgment on that. I've tried meditation, daydreaming, counting, breathing deeply so the belly expands and exhaling through the mouth (from an article in AARP), etc. All work some of the time. Hope one of these suggestions works for you.
Hugs & prayers,