In the USA and other countries, the day after Christmas Day is not a holiday but a normal one. Or as normal as a day might be that follows one which probably involved a prodigious degree of eating and drinking.
Here in the UK the 25th segues into the 26th, which of course we know and love as Boxing Day: not for any pugilistic connections (although there will undoubtedly be those who've almost reached the point of coming to blows with other dearly beloved family members) but because of its rather woolly historical origins.
Some say its name comes from money traditionally given to tradesmen by their customers at this time of year. In the UK these gifts are still sometimes referred to as Christmas 'boxes'. Others suggest it has a much older meaning. Immediately after Christmas the wealthy would permit their servants to visit their own families (presumably once they'd performed their figgy pudding serving duties for their masters on the 25th). Servants would be given a box of goodies by their bosses, to share with those at home, hence 'Boxing Day'.
Perhaps I may make another suggestion however? Maybe today's a good one to think about packing some of your more groundless negative thoughts away in a mental box, consigned to a dusty corner of the attic?
I'm not suggesting for a minute that it makes sense to somehow try and ignore big issues that might be eating away at you at the moment, just that it could be possible that you're also on edge about things that might not really be that important in the scale of things.
Visualise them going into a cardboard box: by all means pack them away with referential care if you like. Then use one of those brown-tape dispensers to seal the lid. Finally pop the box away in a dark place.
If you really need them they'll still be there somewhere; but if you don't, imagine how much better it will feel to have a slightly less uncluttered mind, even more so once the eating and drinking haze has cleared.
Box clever today.