The brain won't shut the fuck up

I'm not sure if anybody reads this, but here it is.

I noticed that some days the brain just won't shut the fuck up. 

For example, I go to bed, trying to be responsible and wake up in the morning fresh and jolly. Everything is ready. But then it's: "Oh, by the way, I need to buy wipes\respond to that email\get my watch fixed\ tomorrow...I wonder where my classmate is. He used to be good a good guy, but then we broke up for some reason...Is there any real meaning in life? ...Maybe I need a new daily planner..." Sometimes I remember something embarrassing that happened long time ago or my mom saying :"Why are you always so clumsy?" or something alike. 

I never figured out how to cope with these thoughts.