A lot of what you mention reminds me of my relationship with my mom, or how it used to be. For my own well-being I had to pull way back. I live far away and keep conversations with her superficial. Mine is completely impossible to try to discuss any issues with. She can't accept that she might be the slightest bit wrong.

It sounds like you are setting the right boundaries. Stick with it! And, you are right, it's not your fault. Hugs!