I don’t think it is any coincidence some of the funniest, saddest and most poignant movies and tv shows revolve around family holiday get togethers, I think your feelings have a universal element.
For many years we resolved at least some of this as DH took the kids to his parents for Christmas, I took them to my family for New Years. In our case it was more in-law problems. I can take my family in small doses, but don’t expect him to endure the insanity. Oddly the kids don’t have any problems with either side they just take what comes.
I confess however there have been years I or the kids have developed mysterious virus symptoms when it was time to drive, and had to stay home so as not to spread the contagion. After a while, we decided to have our own family holiday traditions and home, and visit the families at other times, which worked well for over 40 years. W/O the holiday stress (90% self-imposed by those who obsess about holidays) these visits went much better. I had a job that made a perfect excuse because I worked weekends and holidays. Either your job, your health, or the health of someone you care for make the best excuses. You don’t have to tell them it is your mental health you are protecting.
I will just add a note if you are already stressed out and working to hard, you do need a holiday, just not one that makes you crazy. Can you board out your dog in a reliable place and invent a mandatory “business trip” for a few days so you don’t go nuts yourself?