Yeah, that does sound like a bad work culture. Your description reminds me a lot of my prior toxic workplace and manager. There was lots of favoritism and if our manager decided you had gotten on her bad side, she wanted out out. Her boss was not receptive to any feedback either. When it's the overall environment that's the problem, change isn't likely. I can empathize.

I know the employment situation is not great in a lot of places, but maybe it's time to at least try job hunting.

Edited to add: I actually took me a while to get used to my current work environment where I am treated respectfully and my opinions are valued. I guess, in a way, I got used to the crappy treatment.