I'm another one who understands. I live on another content and haven't been back in years. The last time I went I definitely didn't enjoy the experience. They also retired to a state I dislike and they're the only people I know there, so there's no getting a break.
There's always been something off about my mother (personality disorder probably?) and she definitely likes to push my buttons. These days she has dementia, which has just made her nastier. My dad is more easy going but also is an enabler.
I can't imagine spending thousands of dollars and taking 2-3 flights to deal with that.
I haven't tried the grey rocking some have mentioned here, but I know it's been helpful for some people. Maybe you can read up on that before your trip. I did a quick google search and there's a lot of information available.