Thanksgiving is my favorite holiday, because it's something I've started celebrating as an adult, after living in the United States, where I first got to participate as an exchange student with an American family, when I was 18. Since then, I say my thanks, and have turkey, every year, also in Sweden.
Many other holidays, however, have been filled with stress and tension so much, I have rather spent some of them alone. It's actually something I recommend trying. You can eat what you want, do what you want, go where you'd like, and simply cozy up in front of a book, the TV or your laptop. Notice how relaxing that is!
Nonetheless, the most important thing is to let go of expectations. What are they? And most of all, which expectations of you, do the others in the family bring to the table? These, even subconsciously, will bring forth clashes between how we wish it was, and how it is. Unfortunately, the hardest part is sometimes to acknowledge that there is a conflict. I've even tried to deliberately set all aside at my mother's, when she was ill over Christmas, but only to be nagged by my brother anyhow. If the other doesn't want to acknowledge his/her role in it, his/her responsibility, then spend it apart. How would you like it to be? Communicate this clearly with those you plan on celebrating with. And remember, our arguments are like seasoning - too much actually ruins the food.
You are worthy of peace!