Instead of trying to fall asleep, I try to review things in my head, with my eyes closed.
Sometimes I go over my memory of the periodic table of the elements including atomic weights.
Other times I review in my head the States of the US and their capitals.
Sometimes I try to remember every country I have visited and what sites I saw in each one.
Those are some of the things I review. You will have your own things to review.
DO NOT think about the list of things you need to do.
Don't get frustrated if you can't remember a State capital (you'll get it next time).