I have this problem when falling asleep at night as well... just rehash every conversation I have had(also why I am just antisocial, it's easier)... did use weed to help numb by brain for a long time, but have stopped that. I find the 4-7-8 breathing method for about 5 minutes helps me calm my thoughts and drift off to sleep much quicker. You could try NSDR if you just want to recenter your focus during the day.