Here’s another tactic to add, borrowed from mindfulness practice and cognitive behavior therapy.
Recognize that your thought is “just a thought”, and isn’t reality. Acknowledge the thought, then continue on doing what needs doing. We have thousands of thoughts each day. They needn’t run our lives, because they are, after all, just thoughts.
And from Buddhism: Don’t attach yourself to the result. Accept the doing as doing, and let the result occur on its own, without your worrying about it. Deb Knobelman, PhD