HI, when I was at halls I spent most of my Christmas there, my family life was also very toxic. Not a great many people tend to stay at halls over Christmas, but when your family is toxic and going home would just be bad on your mental health, staying in halls instead of going back can definitely be better for your mental wellbeing, and as such be the right choice.
The big white wall is helpful to find support from peers. It's anonymous and you can also speak to a counsellor on there free of charge https://togetherall.com/en-gb/big-white-wall/
I understand that Christmas time can be difficult, so arrange meetings with friends, plan activities and talk with people you trust and love.