For some it's an annual phenomenon: the New Year's hangover. But there's reason to believe next month's could be worse than usual. No, not the headache that comes from a late night and too much champagne on New Year's Eve. That might hurt for a while, but you'll be fine in a day or so. The hangover with more lasting effects comes from the harsh reality of the holiday credit card bills that come due in January. Some people dig themselves a hole in December that they spend the following year trying to escape. And again, 2013 is shaping up to produce a particularly nasty financial hangover.