You can celebrate the holiday when you get to see her next. I know it is hard, but the long term is more important than 2020. Wrap her gifts; get a tiny fake tree or menorah or whatever your symbol is; set out the decorations to be put up, ...
Many of us (think military families) cannot celebrate special days on the exact date so we do whenever our loved one is home.
You absolutely MUST find legal assistance for your DV case. Try your local law school clinic, call the bar association, beg to borrow from relatives (be sure to pay them back), ... At the very least, some attorneys offer a free or low cost assessment of your case; some may take payments,
To make the day less painful, work overtime or on extra holiday pay dates to keep you occupied.
If you are able to contact her (not by telephone but by a traceable source like email, text, ...), ask to see your child over the holiday. A refusal on her part when you are no threat to the child looks bad for her. It would be totally reasonable to ask for any court ordered holiday time as long as the PO does not include your child.
