I have two tools that I use to fall asleep, and they have been working pretty flawlessly for me over the years. The primary one is reading a book in bed, when I’m off to sleep. Usually it’s not a lot of reading, I get pretty sleepy after 10-15 pages. The other is supplementary to the reading and that’s imagining some fiction scenario in my head. For me, it’s some simple SciFi or fantasy scene or whatever and I try to visualize the characters, scenery, etc. It’s usually just enough to occupy my brain enough so that it doesn’t do its thing of running around wherever it wants to, and just not quite enough to give it fuel for active engagement. No idea if either might work for you, but maybe give it a go if you haven’t already.