Share the tasks: you don't have to do everything yourself. Spend time with friends and family while you share tasks like decorating, wrapping gifts and preparing the holiday meal.
Learn to say no: it's ok to say "no" to events that aren't important to you. This will give you more time to say "yes" to events that you do want to attend.
Take breaks from group activities: pay attention to your needs and feelings. Spend a little time by yourself if you can. Meditate, or do some relaxation. Go for a short walk.
Get support if you need it: holidays can sometimes trigger depression. You may think you'll get over "the blues" on your own but most people need treatment to get better.