Hello Selina91,
I don't have a great deal more to offer than what Skeezyks has said (good suggestions, especially about having several people run interference or act as a buffer zone). I would like to pose a question in the gentlest possible way: do you really have to spend time with this person? I know the holidays involve family and the answer may be that it's unavoidable if you want to see the rest of your family over the holidays. But I still had to ask. Having to spend time around the person who abused you must be very very difficult. Please know that I'm sending good thoughts your way.