I had a similar problem with melatonin. I find the bi-layer melatonin works better for me when I just can't sleep. There's a fast-acting layer to help me eel sleepy, and a slow-release layer that hels me sleep all night without waking up.

But needing melatonin is an exception. My routine includes other non-chemical things. No single one is a magic bullet but together, they work for me. i hope these ideas help someone.
I try to get some exercise in the late afternoon or early evening, so I'm feeling kind of good-tired by bedtime.
I turn off TV and all electronic screens starting an hour before sleep.
I follow the same before-bed routine, at the same time , every night.
I have a little SAD light I bought for $30 on Amazon, and use it in the short, dark days of winter. I sit by it every morning while I read emails, plan my day, and watch the news. It wakes me up, then I start to feel like slowing down and going to bed on time in the evening.
I just go to bed when I start feeling sleepy. If I stay up just a little longer, and then a little longer, I get a second wind and then I'm wide awake for a few more hours.