Commercial Christmas stops 25th of December.
Years ago, I have wrote some posts about Christmas blues and I had a problem like you.
I do not know, really do not know, why US stops celebration of Christmas on Christmas Day. The same is in my country, but it's not so radical like in US. This is some kind of paradox, in US Christmas season starts after halloween and I really do not see the reason why it should not be prolonged for 12 Days, as it should be. We have all the right of the world to celebrate it. So, as someone wrote it, just do it.
My way, of fight for this blues is:
1. I do not rely on tv or radio stations anymore, so I have blu-ray movies, CD's and enjoy whenever I want in music, movies... I make a list of movies that I didn't see on tv, and I watch it on blu-ray and listen to musicans that I didn't hear so often. i.e. Wille Nelson - Pretty paper
2. I have written some mail to my city authorities that the lights should stay up, min. till Epiphany, nowday they are light up till end of January. It's really not a problem if you explain to reasonable people.
3. Shops, TV commercials, etc... We can not affect on that, but they are just here for earnings, not for Christmas.
It's all about you, if you finish Christmas in your head, then it's over... And Christmas is in YOUR heart, not in the guy who is DJ on radio, or tv producer who chooses which movies will be aired...
We need to fight for 12 Days of Christmas, first in our head, then on the streets.
I will repeat, we have legit right to celebrate Christmas 12 Day, and the seasons have just started, so enjoy it, don't be blue
Make a cup of hot chocolate, or Christmas tee or better muled wine with cinnamon... Light up the tree and enjoy... Christmas is NOT OVER! Fight for it