I’m deeply sorry to hear that. I have been in your shoes for five years straight. This is the first time I spend it in family since forever.
What I would usually do, is to prepare a very nice movie, or a great videogame I kept aside for a special occasion, drink wine, eat chocolates, the whole heartwarming exercise.
Other years, I would play a MMO and have a play/chat with strangers bored to death at their family gatherings.
I guess Christmas Eve is about giving. So my advice is don’t give up on you, you deserve to have a good time, no matter what makes you feel warm.