Do something that brings you into your body and out of your head. Dance, music, exercise, meditation: all these practices encourage you to take your attention away from explicit verbal thought and focus on your somatic experience. It will be difficult at first: your mind is a muscle, and its currently in the habit of listening to itself talk, but the more you practice rooting your attention in your body and it's experience of the world (which is far, far richer, by the way, than we're usually aware of, thanks to our predisposition to thinking), the better your right hemisphere will be able to inhibit your left, and your mental chatter will begin to quiet, allowing you to be more fully present and focus on rejuvenating activities. (Don't worry -- when you go back to work, you'll be able to pick right back up where you left off, only you'll be more energized and balanced.)

If you're into it, here's an (hour-long) intro to mindfulness by Jon Kabat-Zinn, a well-known name in Western meditation circles (he basically rebranded meditation as mindfulness to bring it into Western medicine): http://www.youtube.com/watch?v=3nwwKbM_vJc