Change your mind. Optimists outperform their glass-half-empty counterparts, according to psychologist Martin Seligman. If negative thoughts leave you paralysed with self-doubt, reframe your challenge. Replace 'this is impossible' with 'this is an opportunity to learn' and defy the naysayers.
Use your allies. Market research firm Gallup found that having a good friend at work fosters sustained performance. Whether it's reassurance that your strategy makes sense, or a pep talk before your review, seek the support of a trusted ally.
Hide away. Close the door, minimise your e-mail browser, unplug the phone, disable all channels through which worry might ambush you.