Ugh sleeping issues and nightmares are the worst. I have a lot of trouble with sleep, so I really feel your pain!!

I have found that binaural beats work pretty good, if you can tolerate having headphones on while you sleep. Idk what phone you have, but I know there are several free apps in the Google play store, and there are probably apps in the itunes store as well. I want to get headphones that are like built into a headband or something -- that way it would be comfortable lol.

I used to take melatonin and it didn't really have much of an effect for me. My doctor told me that for it to actually work you need to have a build up of it in your system, aka you have to take it every day for a few weeks before it even starts to work. Idk if that's true for everyone, but it didn't do much for me either way.