When you sit down to write, write. Don't do anything else except go to the bathroom, and only do that if it absolutely cannot be put off.
Stephen KingThere's something in us that is very much attracted to madness. Everyone who looks off the edge of a tall building has felt at least a faint, morbid urge to jump. And anyone who has ever put a loaded pistol up to his head... All right, my point is this: even the most well-adjusted person is holding onto his or her sanity by a greased rope. I really believe that. The rationality circuits are shoddily built into the human animal.
Stephen King