Someone asked me what my favorite holiday was and all my brain had was a flashing 404 - Data Not Found code.
I don't have happy holiday memories from my childhood. The happiest one was when I was six and got a microscope and a sled at the same holiday, but it still a traumatic memory.
My memories from adulthood are shaped by those early memories. I'm sure there must have been some good holidays, but the majority of them were dominated by tragedy, abuse, or other trauma. I've had better experiences as an adult, but the shadow remains.
You can't shake off the trauma of childhood. You can address it. You can get counseling. You can recover. But you can't erase it. It's always part of your life and it will color your adulthood.
It's okay not to have a favorite holiday as an adult. Or to not love your birthday party.
Find other things you love. Pick other days as your favorite.
Let yourself move on to a better future.