i've had sleep problems all my adult life, and expected that alcohol was the reason and that this would all get "better" after i stopped drinking. eight years later, i still have sleep problems. no trouble, ever, falling asleep, but staying asleep.
tried most every recommendation: no screen-watching at night, no caffeine after 3 pm, calm evening, only sleeping in the bedroom, going to bed at same time, fresh air in room...all that is recommended.
the only thing that really is working for me is something i read by chance in an old "sleep" book i randomly opened in a thrift store, and it said that our intake of Cal/Mag is way too low, and should be at least 1000 mg at bedtime. i'd taken a calcium/magnesium pill at bedtime for years, just as part of my daily vitamin-thing, but then i tried the much larger dose. expecting nothing, i was floored. i slept. only woke up once, for a few minutes.
it's not perfect, but sooo much better for me most every night.