I do think there are times when it is helpful to take a break from therapy, to skip a week. But I know there are also times when we need to go to therapy but are avoidant because it will be difficult or painful or challenging or whatever. The trick is to distinguish between these two. If you really feel skipping a session would be beneficial and isn't just avoidant, I think it is best to be honest with your T. Don't make up excuses about being sick, just call T and say, "I really need a few more days to process before seeing you again, so I'd like to cancel our session tomorrow. I'll see you next week."