I absolutely relate. I have so much compassion for what caused my parents to be the way they are, and for how blind they are and how badly they fuck up, all the while believing they're right. I've written several threads working through a slightly different issue -- their feelings aren't a block, but the issue was whether or not to leave a letter as I know they will be impacted, yet no matter what I say, their filters will skew it.
I was being internally beaten up about how they're going to suffer and my ostensible need to address it, yet no matter what I do that is honest and doesn't take away from my self respect, it won't make the impact I desire. I'm 49 years old, and I have simultaneously loved and hated my parents my whole life. It varies in intensity and I'm much more grounded than I've ever been, but I'm still impacted by it. I try to stick with non-attached compassion -- I care, but I didn't cause their problems, I can't cure them, and I can't control them. I have to let them deal with their own emotions and problems.
Although they will experience it this way, if I suicide, I am not doing anything to them. They think everything I do is something I do to them, especially doing anything for myself, anything that is freedom or establishing a boundary, anything to do with my own autonomy, or even making a mistake that only impacts me. It's fucking insane. And they claim to be so normal and moral.
I have no idea if it will serve you, but I have an active thread in Off Topic about my parents. We have not been in contact for several years and they pushed a boundary to the point that it required me to enforce some pretty serious consequences. It wasn't easy, I took no joy in it, but it was necessary. If you care to read it, there's a letter in a spoiler in that thread. I sent it to some of their friends and our extended family. What's particularly relevant when I think of you is the paragraph toward the end about silence. It's about what they believe they have the right to do, and that I'm no longer allowing it. It's helped me make a mental shift, perhaps there's something in that thread or in that paragraph that can serve you.
Anyhow, I've written multiple threads processing about my parents. SS has been a great place for me to do that. I'm really glad you posted this thread, and I'm glad I was able to relate. I hope you get something great out of having posted, if not from me, than from someone else.