I think what you feel is fairly normal. The build up to christmas is so big.....and starts so early now! That I think lots of people feel deflated on the day/ after it. Most of us experience a change in routine leading up to Christmas....most of us are making extra plans, spending extra money, maybe doing things we wouldn't normally do throughout the year....it feels "different" and "special ". It's almost like the feeling you get after a great holiday!
Theres also a lot of pressure. I consider myself THE most laid back person, but evey year just before Christmas I fall out with my husband over something ridiculous. We're not perfect, we rarely argue...but without fail...Every.Single.Year. And I can only put that down to the pressure that I/he/we feel?
I wonder every year, when I put my tree and decorations away, what will the next 11 months look like. I think that's pretty natural and common. I take heart in the fact that these are all "very normal" emotions and I think you should too
I dont feel any pressure about the coming year. I must admit I stay off social media a bit at this period....i get a bit fed up with the christmas dinner/decorations away/new year,new me/end of year look backs etc. Not that I'm not pleased for all those that want to share these things, I just find it a bit meh, another one.
I throw myself into my house a bit, I start clearing and sorting. I try to find solutions to everything in my house that annoys me lol, I guess I just throw myself into other things rather than dwell on it being a new year and all that is coming. It is what is really so just go with it if you can.