I understand your anger and your hurt. Your husband made his choice. He certainly didn't condsider you or the children when he chose to stop working on his recovery and start feeding his addiction. I'm sorry that it came right before Christmas but there never really is a good time for a relapse...
Your husband has all the tools he needs to recover and live a full life but it doesn't sound like that is what he wants right now. You have choices too. You can get your joy and your stability back when you are ready. You can choose to focus on your children and yourself, or focus on your husband and what he is doing.
Do you go to Alanon?
One foot in front of the other... move forward with your plan. Trust that what your head tells you to do is the right thing to do. Trust in your boundaries.
It doesn't sound like your husband is going to be much company on Christmas anyway - strung out and drugged out. If he chooses to get clean then he will have to detox which will make him a bear to be around. And if he chooses to keep using, then you have your boundaries that you need to work on.
I hope you can make the best of it. xxxooo. There are lots of people here who understand what you are going through so stick around.