Treese, I second M's advice to you. Be unavailable. It's not your place to bail his sorry rump out of the mess he's gotten himself into. You have enough on your plate with your children, the fall out of this mess, work and yes, even taking care of yourself.
As for Thanksgiving....sob, get it out of your system this morning and then enjoy the rest of your day w/your family. Your family are the precious jewels in your tiara and you need to be all you can be today to keep them on an even keel. This is just as difficult for them as it is for you and to have that fool tm you to lay the guilt at your doorstep on Thanksgiving is just too childish and immature.
Do not feel sorry for him. He's the one that created this mess and now you and your children are feeling the effects of what he's done. Protect your assets as you do not have to bail him out. The judge is going to have a nice chat w/him about monetary responsibility when the day comes. You are not going to be responsible for that support...he will.
One more thing....if he starts raising the issue about the divorce or child support...point out it's a holiday and you do not want to discuss the issue w/him during this time.
Please try to have a good day w/your family. I know it started off terribly, but hopefully you can enjoy the rest of the day.