Remember that the current dates that have been determined to celebrate holidays like Thanksgiving, Christmas, Hanukkah, Easter, etc are not necessarily the actual dates the events happened. I mean that Jesus was not actually born on December 25th in America, so you can choose to celebrate on different dates and it doesn't have to feel like it's not as real as the proscribed dates. So if you end up being forced or guilted into going to a family get-together on December 25th, that doesn't have to be anymore important than the gathering of friends you have on December 18th or 26th.
Getting back to the real meaning of the holidays can be difficult and controversial. For example: Christmas has become a hugely commerical celebration costing people a lot of money. People talk about saving all year to buy gifts or taking themselves further into debt they can't handle. How does this have anything to do with celebrating the birth of Jesus? Why is there so much resistance from families to change this? I tried to get my ex husband's family to set a limit on the spending and they got agitated and refused to change their system even though it meant family members were going to be hurt financially.
It's always important to remember that you have OPTIONS to choose from:
You can say no and make your own plans
You can set limits on your spending and your time even if others choose not to
You can make your own plans that feel more rewarding and focus on them
You can celebrate holidays on different dates and still find joy
You can propose changes to the yearly rituals and expect to be respected by having your proposals considered seriously
You can talk to a therapist and figure out why the holidays are so emotional for you and find ways to let go of the past