Scholastic.com offers advice for beating holiday stress for teachers. Here are my faves--

Keep in mind that no matter what colleagues, your principal, students, or parents think or say, you're basically a good teacher who can't please all the people all the time.

Think of things that make teaching fun for you - and do them!

Give yourself permission to do absolutely nothing for five minutes a day — and not feel guilty about it.

Be grateful to have a meaningful job.