Too much brain chatter

At the end of a much anticipated event – be it a party that planned for, a big presentation at work etc , my brain gets into a lot of thoughts both positive and negative about the event …it’s a lot of thoughts to handle and thought download won’t quieten it, it’s so loud and noisy up there that I can’t sleep. I buffer by reading a book and fall asleep. I’m not sure if I’m buffering here since I don’t want to stay with positive thoughts either ….Any other ways to shut down your brain without buffering ?