@Gargron

The best thing I have found for getting to sleep and getting back to sleep when I wake up THINKING - is to listen to a good audiobook read by a good reader.

I put all the chapters/episodes on a playlist and remove the chapters I have heard all of as I go.

I leave it playing all night. In the morning, remove heard chapters, mark the whole playlist unread, start the next episode and go to where I don't remember it. All ready for next night.

REALLY good reader:
https://librivox.org/search?title=&author=&reader=John+Greenman&keywords=&genre_id=80&status=all&project_type=either&recorded_language=1&sort_order=catalog_date&search_page=1&search_form=advanced