IANAD, and this is just what I do:

PM: Magnesium (multiple forms), melatonin, l-theanine. AM: Vitamin D (from sun preferably) in the AM, moderate exercise 5 days/week

Diet: keto / low-carb

Also: Get checked for sleep apnea. Use Oura or a similar sleep tracker, preferably find a good one for SpO2 (Oura does not)

Good luck. Finding good sleep in modern society is hard.