I have a couple of things I do, depending on the night/mood I'm in:
One of the things I do is to throw on some relaxing music for myself with a coffee (Decaf if you can't drink caffeine before bed) and go to a park or somewhere quiet near my place and listen until I start to feel like bed is a good option. It might be some Chopin, Ravel, Debussy, Prokofiev, Cage, Glass, Feldman, Schoenberg, Brad Mehldau, etc.....
Or, if I need something a bit more energetic to start with after a long night of hard music (or if I've been drinking), it might be Koop, Nick Drake (really good on melancholy nights), Mark Farina, Portishead, Bill Evans, etc....
Sometimes, if music doesn't work, I find something I want to learn or become better at and I learn. The problem for me, in this case, is that I sometimes get into long stretches where I don't want to tear myself away from the computer or the book. Late at night is a really good time to start learning electronics or music theory or get through some poetry or short stories that you've wanted to.
I used to have serious issues getting to sleep and I don't drink heavily or take sleep meds, so I understand where you're coming from. I used to have nights where, after 10 hours of classes, I couldn't get to sleep at all and ended up staying up for days, working on pieces for class or various other assignments. I had to learn to force myself asleep for my own personal well-being.
Here are some pieces that work for me (musically) sometimes when I can't get to sleep. They might work for you too:
‪Nick Drake- Riverman‬‏ - YouTube
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‪Koop- Waltz 4 Koop‬‏ - YouTube
‪Brad Mehldau - Paranoid Android (Radiohead cover)‬‏ - YouTube
‪Maurice Ravel - Menuet - Le Tombeau de Couperin‬‏ - YouTube
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Hopefully you find something here to help you.