Kava tea. It doesn't mix well with some meds, but I haven't had an issue. You can buy it in the grocery, Yogi brand is one of them. I use bulk rough-ground root.
Meditation.
Breaks from the chaos. Just walk away for a while.
I don't recommend drinking your way through it. I've done that several times and it just made me worse when I sobered up.
Patience with yourself and moreso with others.
Regular sleep.
Have one room, minimum, with no holiday stuff in it. Use that room for respite.
My favorite, and the only tradition I truly like about Christmas, watch "A Christmas Story" as much as you can. It really does start to get very funny about the fourth time in.
If you craft, make something for yourself first.
Don't overdo it. Just don't.