God, aren't the holidays wonderful?!
I sympathize with your plight! So, coping strategies . . .
1. Take along something you particularly like to drink to help you avoid any alcohol?
2. Multiple brief outdoor escapes to breathe and destress?
3. A mantra to say to yourself for strength and calm?
4. A mental database of several things you find hilarious -- scenes from a sitcom or movie, jokes, anything you can think about to make you giggle inwardly and momentarily break any tension. Picture everyone naked?
5. Inspirational quotes to say to yourself? One I love is Julian of Norwich's "…All shall be well, and all shall be well, and all manner of thing shall be well"
Just some thoughts. Remind yourself that it's only a few hours, and even though it's hard, discomfort won't kill you. You can do it!!