I think many people suffer from an "after the Lord Mayors show" feeling after Xmas.
During December there is a big build up to Xmas and the New Year with buying presents, putting up decorations, buying food and preparing for the holiday period.
Then when it all finishes, and the decorations have been put away, we all feel a bit flat.
So the thing is to have a few days getting over it all.
Then try to look forward and plan what you want to do this year.
What thing do you want to achieve this year.
Think about what do you want to do to your house, where do you want to go on holiday, what new skills do you want to learn, what new things do you want to get involved in this year and so on.
Plenty of local colleges start short evening classes at this time of year so think about signing up for one of those. It will get you out the house, meet new people, and gain a new skill.
Go to your local library and look at their noticeboard which will show all the local clubs and societies. There is bound to be some group that meet up on regular basis that you have an interest in - such as gardening, walking, chess, bridge, reading, steam trains or whatever.
So don't sit at home, get out a DO something with this year.