One of the doctors I have learned about in my quest to improve my health is Daniel Amen. He runs a number of clinics focused on optimizing brain health and decelerating the aging process, among other things, and one of his recommendations is this:
Don’t believe every stupid thought you have.
The brain is noisy, and skews negative. There is no imperative that you must believe every thought that is rattling around up there. Instead, ask yourself, “is it true?” This will help reframe the thought, and re-focus your mind. I have found this helpful and I hope you do too.