Oh PJ, thats sad, I must say Im in a similar position, my son always go to the Mother in Laws - the wifes side. I know its natural that this should happen but I do get hurt,never havea Grandchildren over for Christmas- know I shouldnt but I do, I end up feeling cross and sulky like a big Kid.
Do you have friends near by that you can have round for a few drinkies? Helping others has helped me cope with anxiety- gardening at the sheltereed housing down the road, helping dish up Christmas dinner at the Sally Army or homeless charity. What about local animal charities- they always need help. It does make you feel needed and wanted and that matters. do something indulgent- Champagne and lobster in front of the telly, watch whatever you want. Spoil yourself. Theres no rules here!
Anxiety isnt nice, youve done so very well to manage it, Christmas is a hard time- puts lots of undue pressure on everyone. dont beat yourself up about things beyond your control.
I'm sending you a hug right now... there, hope you got it.