Have some fun. Balance work with play each day, if possible. Take one thing at a time. When you're tense you may see a mountain of problems and tasks in front of you. Choose just one thing and deal with it.
Chances are other things can wait.
Learn to say no to requests that you can't reasonably handle, and don't feel guilty about it. Don't bottle up anxiety or anger. Talk it over with someone you feel comfortable with. Set reasonable goals and expectations for yourself. Revise them often.