[KC Jones]

It's probably been mentioned previously in this thread but...

It really depends if your problem is falling asleep or staying asleep how you approach this. I can fall asleep with no problem but I am up a few hours later. If you can find something that helps you get the right sleep pattern every night for 2-4 weeks you can re-program your sleep cycle and should come through it and be ok. At least for a while.

Get as much natural light as you can throughout the day.
Excercise in the mornings, not at night (although something like stretching in the evening is good)
Reduce your screen time - especially in the evenings. For 2-3 hours before you want to go to bed, don't look at a screen.
Book reading in the evening is great. Paper book, not on a screen!
Get cold before you go to bed - avoid a hot shower or bath, keep the temps low at night.
Melatonin - I've had no success with this but others swear by it.

Anything you take to help you sleep - your body will eventually adapt to and it's effectiveness will wear off. It's important to consider them just stop gaps to help you re-program your sleep cycle. I avoid most of the prescription stuff because the side effects can be brutal. Benadryl is not habit forming and other than being groggy in the morning it's got no real side effects. It's cheap too. You can take a lot of it without any concern (4-5 pills each night if your tolerance gets you to need that much).

Hope this helps.