Over the years, I have learned that rather than having no empathy, some people just can't handle to see suffering that they cannot fix. My father would always turn off the television when he saw the starving children advertisements. He always seemed annoyed and I thought he just hated the people asking for money. Then one time when he was a little tipsy after a few drinks, he started talking about the problems of the world. At one point he talked about how starvation had to be the most horrible situation and how sad it was to see in children. I was very surprised but realized that some people are just inhibited when it comes to handling their emotions.
In your case, you might get along better with some of your friends by putting on a brave face instead of sharing your troubles as much as you are. Consider it a way for you to accommodate their disability.
I do hope you feel better as the holiday season progresses.