I suspect that Descartes got it wrong. He said ‘I think therefore I am’. It should be ‘I am and thinking is one of the things I can do….or not’. We probably can’t stop thinking but we can decide on which thoughts to entertain or focus on. Sometimes these thoughts morph into feelings and action. If you have unhelpful thoughts like ‘I can’t speaking in public’ ,the old way was to dispute this thought or distract yourself when the thought entered your mind. Didn’t work did it? The thought just kept coming back. An alternative strategy is to live with the thought. Make room for it. It will leave eventually and be replaced by other thoughts.Identifying it as merely a thought will reduce its impact on your performance. Try saying to yourself ‘There’s that thought again’ or I notice that the thought ‘I can’t speak in public’ has come back. Try it. Put your full attention into everything you do.