Melatonin may still be your answer. The dose needed varies greatly from person to person, but you will know when you've gone too high as you will get vivid nightmares (my hubby thought a wolf was ripping at his throat). However, backing off at the dose before "the wolf" has really helped him. He also is on CPAP (I try to think of the whooshing as ocean waves-I try.) He also takes Benedryl sometimes when it's late and he doesn't feel sleepy yet, though I am not sure how much this actually helps REM sleep and what the long term issues could be with that.
I take Klonopin at bedtime. It is longer acting than some of the other benzos and I find it helpful. Trazadone gave me akesthesia (sensation like you have to move all over-like full-body restlessness) thus NOT helpful. Refused Seroquel and can't take tricyclics as I am on SSRI's for depression. I do play sleep CDs or nature sounds in the background at night as it helps me relax and meditate before sleep and covers some of the CPAP from hubby.
I also am a total convert to a body pillow. Hubby hates it as it looks like I'm rolling around with a whole other person, but I find that it keeps my body aligned and I toss and turn less when I'm not twisted on my side.
Hope this helps,
Lori Lee