Do the usual nothing until you find something to do.
"When it comes to artist block, and you are stressed out and anxious all the time and there is a deadline and you just can’t get into ‘the zone’ no matter how many coffees you may have had, just leave. Go see a movie. Go driving. Meet a friend. Get drunk. Have a nap. Do anything other than sit in front of the computer or easel or whatever. Just don’t think about it. I find that if you force it too much then it’s a crap time for everyone. It is no fun and the artwork suffers.”