Hello.
I know that empty feeling you are talking about. I find the few days right after Christmas are the hardest to keep the spirit alive.
As far as keeping Christmas cheer all year:
We have one Santa decoration that stays up in the living room all-year long. That really does help. I can always look at Santa and I light up with joy.
I also listen to Christmas music all-year round. Not all of the time, but when I am in the mood for Christmas music, I listen to it; especially when it snows. During the summer, I listen to Christmas music when I mow the grass. It took my wife a little while to understand my Christmas music habits, but she gets it now. However, unless I am home by myself, I use head phones.
Another great way to keep Christmas going is to celebrate Rudolph Day on the 25th of each month. Watch a Christmas movie or some other Christmas type of activity. This is going to be something I do for sure this year.
The best way to keep Christmas cheer alive (and I am going to sound like a commercial here) is to stay active on the forums here. We are all in the same boat and help each other throughout the year. Check out the daily winter/Christmas pictures thread, this thread of course, and explore the others. The sense of community is amazing here and it really helps on those days when you are not feeling Christmassy.
I hope some of that helps.