Holidays, Christmas in particular, can be an exceptionally painfully lonely time for so many people and it's kept quiet so often. I think you will find from your discussion that many people are unhappy and not really looking forward to Christmas.
It's particularly hard because, all the songs are playing "It's the most wonderful time of the year"... The shops have all their bright colors and decorations, small talk always comes back to "have you got everything for Christmas are you ready for the holidays, have a great Christmas".... And you're like, no. It ain't going to be great. I'm not looking forward to it.
Not a lot of people will talk about it, but there are tons of people out there who have just lost a loved one and are facing their first Christmas without them and it is absolutely earth-shatteringly heartbreaking for them.
And then there's the smaller but still terrible losses of divorce / separation/breakup or a loved one being away for the first time during the holidays and can't make it home for whatever reason,
Or some other major stressor like just having found out you've got a terminal illness, or finding out you're going to lose your job, or finding out you're about to lose your house, and there's so many people who are in this situation but most of them keep quiet about it, and as a result all your hearing is "It's the most wonderful time of the year"....
And you feel so alone. And it's really really hard. And I'm wondering if this discussion, other people will let you know that they're also going through some tough times and, even though you feel alone, your situation is not unique, you're not alone, and there's a lot of people feeling as you are, so don't feel like the whole world's out there celebrating and you're not. When you're out there in public, I guarantee you at least 25% of the people are smiling fake smiles, they're not really happy about the holiday season approaching.