The best remedy for a "blue" Christmas is to find yourself someone or some thing in which to make some form of contact, human or not. There is a big difference between being alone and lonely. Being your own best company is a good thing, but it isn't healthy to let yourself lose connection altogether. Humans are social creatures and we usually do feel better when we put ourselves out there.
The whole message behind the Holidays isn't just having a special someone and spending a lot of money for that "ooh aah" gift. Don't get caught up in the romantic illusion of the season pushed upon us by secular Christmas music, jewelry store ads or the movie industry. Look a little deeper into the eyes of a good friend, a beloved pet, or the sparkly eyes of an excited child, and you'll feel a remarkable connection.
Open yourself up a bit in public settings. Get past those first awkward, out of place moments by making eye contact and being the one to begin a conversation. You may find that oftentimes people aren't cold at all, they can be just as uncomfortable as you and need a little boost.