Like you, I loved Christmas as a child, my parents made it so magical! But as an adult I've grown to dread it because it just leaves me feeling sad and lonely because I don't get to join in the magic.
I don't have any children, not by choice, and I'm single, so I don't get to be part of the magical Father Christmas aspect of it, and Christmas is the time I feel hurt by infertility the most. If you have kids, you cannot imagine just how many times people feel the need to comment on how Christmas is really for kids.
My siblings do have kids, and live away. I make a point every year of inviting the whole family to spend Christmas in my home, but because of the hassle of travelling with kids they have never once accepted the invitation. My parents also (obviously) choose to spend Christmas with their grandchildren. So this means I have never been the "host" for Christmas, and I realise hosting is not for everyone but it's something I dream of doing.
I either travel to them instead and spend the time on a sofa or tiny spare box room, or stay home alone.
Throughout December I am proactive in arranging lots of fun social activities with friends, I love to go out. But invariably, more often than not, friends drop out because their kids are sick, or they can't get a babysitter, or their partner is sick, or they've realised how many presents still to buy and need to shop instead, or they are so tired from meeting so many people and could we meet in January instead (when I know they will cancel again due to lack of money).
So, yes OP, I get you. It can be a lonely and difficult time for some people.