Sorry to hear about the insomnia! A few ideas:
1. Cut out all caffeine for at least a few months. Don’t even eat chocolate (which contains caffeine and the stimulant theobromine) other than in the morning.
2. First thing in the morning, get bright direct sun in your face. Obviously, don’t make yourself go blind by looking directly at the sun. But getting this bright light from the sun early has bee shown to reset your circadian rhythms.
3. Reevaluate your medications to see if insomnia is a side-effect of any of them. Change medications or cease them if necessary (obviously that should be done in consultation with a doctor).
4. Get some good exercise but only in the morning. Don’t do anything more strenuous than walking past mid-day or so. Exercising gives the body adrenaline, which acts like caffeine but is even more long-lasting.
5. Make your room extremely dark, with no light whatsoever. Get new blinds, or even duct tape thick cloth against your window if you have to.
6. Try visualization techniques in which you feel each part of your body get very tired and relaxed.
7. Even better, either in your head or softly whispering, thank Hashem for every little thing you can think of, over and over if necessary, until you fall asleep. For some reason this is very relaxing, and a little boring, so it can work really well.
8. Make sure to eat enough before going to bed, but not too much that you’re too full or that you’re not hungry for breakfast when you wake up. Try having something with carbs, protein and fat, like bread with peanut butter or hummus. (Hummus is good because it has a little garlic, which is a slight sedative.) Don’t drink water past 2-3 hours before you plan to go to bed. You might wake up in the morning really thirsty, but that’s OK.
Hatzlacha!