This whole Christmas thing is meant for us to remember the intervention of God into our lives to bring us to Himself. We have, or I have, at times used the presents we give to remind us of that gift. But we forget that.
So after all of the emotions spent yesterday, on perhaps the wrong things, it would be reasonable to expect an aftermath of down emotions.
If that is the case, one way to adjust is to remember why we are doing all of this in the first place. Use the time from now to the end of the month to invest some extended time in the Word and prayer asking Him what He wants you to do differently next year.