Read the Inner Game of Tennis by Gallwey. He explains how overthinking about your strokes will stiffen your muscles, which will keep you from playing your best. Also, he discusses on detail about how instead of critically analyzing yourself to improve in whatever you are doing, you should make neutral acknowledgements of strokes in order to keep an unbiased insight of the problem. Anyways, some of his insights might help you out with your problem of over analyzing yourself when you play.
Prince Tour Diablo