Well, I'm hesistant to offer any suggestions since I've only had experiences with youngesters in school (and kids of friends) but:

Colouring books? Paints? Could get a bit messy, but I know painting calms me down!
Maybe making a snowman or a snow fort? I don't know if that's really Christmassy, but it sure is fun!
Watching Disney movies! Best thing ever!
Easy puzzles?

I'm sorry that Christmas is so hard on you.