The holidays can be a really tough time. The advice I often heard was, "Volunteer at a soup kitchen. Help others. Get out of your head." It's perfectly fine advice, but unhelpful if the mere thought of interacting with people is overwhelming. Anyway, here's a thing I did one year that did help:

I bought a Cookie Monster costume, went to the airport, and waited at arrivals with a sign that said "COOKIE"

Didn't have to talk to anyone and boy did I get to watch people's faces light up.

@kims The one time I dressed up as Plankton from Spongebob Squarepants for an open house at the marine science institute where I worked at the time, I had LOTS and LOTS of interaction with little kids. And was a popular subject for cameras. I guess airport waiting areas don't encourage social interaction in the same way though. :)