I'm in the same boat as well. This holiday is always the worst for me. Since I don't celebrate x-mas with a dinner, no worries there, but TGiving is a big family affair and lotsa food. Bah!
This is what I'm doing to get back on track: making a plan of what to eat today that's similar to what I used to eat in terms of portion sizes and veggie content. Back to calorie counting (or your preferred method). The best thing to do is make a plan and write it down. That way it's staring at you in the face and it's harder to ignore.
Good luck!!! We can do this!!!