rachriv- sounds hard. But perhaps you could make new traditions. Such as coming over during Xmas to see your family. You could bring them chanukah cookies and presents and light the menorah if they fall on the same day.
There are many ways to show them that you love them and enjoy their company. If you shouldn’t exchange gifts than suggest a secret santa or as we call it “secret friend/pal” or give them chanuka gifts.
You can’t eat the meal or xmas cookies, so make them cookies or buy them with white and blue icing.
During other Jewish holidays invite family members to come whereever you live and teach them and show them about the wonderful traditions we have. Traditions are just something we do over and over to signify the love we have for the people we do it with every year. Show them your future sukah, arba minim, etc.
It will be hard, but I think doing some of these things can help soften the blow. Ask your Rav what are some ways you can make traditions and be with your family in honor of FAMILY and not Xmas.
Wishing you luck.