breaking their rules and setting firmer limits

[desertpine]

My FOO has an unspoken family rule that is tightly woven into the scratchy fabric of the family system: "Never say or do anything that might upset, embarrass, or hurt your mother." It is based on some unspoken beliefs that she is infallible, it is up to the family to regulate her self-esteem, and since she tried her best -she is the best. Well that last part has been spoken on many occasions, usually to reprimand me for suggesting she did some things that were anything other than extraordinary.
Over the years I have become more assertive and set tighter limits around triangulation in the family. Of course, this has lead to push back. And so I set firmer boundaries - including going NC with siblings and low contact with both of my parents. But this weekend I did something for the first time - I directly asked my mother to get help from a therapist because her difficulty with empathy is painful for me and it is jeopardizing our relationship. I also set a hard limit that if I get another message from her husband in an attempt to speak for her or to be a go-between, then I'll block his email address. His communication with me is 99% of the time as a FM. I've repeatedly asked him to stop but have never told them what the consequences would be if it happened again.
My mother and I only have contact via email and an occasional text or brief phone call. And her husband will only use email to talk to me - even then, it's been only a handful of times over the past couple of years. I regret or at least have 2nd thoughts about some of the things I said but that's mostly because of the anxiety I feel from breaking the family rules. I don't think I actually said anything that a normal person would find mean-spirited. But she is narcissistic and so she sees everything as either approval or rejection or her personally.
I feel glad albeit worried about the possible repercussions. But I also feel confident that no matter what they decide to do, like ostracize me for breaking the family rules, I am ok. I can keep myself safe. As an adult I have autonomy - it would be sad if I had to go NC because of how toxic they are, but I would still be ok. In fact, I'm anticipating that I will have to end all contact over the course of the next year in order to protect myself from the hostile messages and manipulative attempts to get me to follow the family rules.
 

[SaintBlackSheep]

I don't have anything meaningful to respond with here other than solidarity, but wow! I could have written your post. We may be siblings because I think we have the same mother lol! I have no siblings to triangulate with, and I am currently unintentionally NC with my parents after setting some boundaries that they did not like and they haven't talked to me in 6 weeks now. That's the longest I've ever gone without talking to them!
I really relate to your whole post, especially the parts where you are anxious over stating things any normal human would state, yet you know your nMom is going to take them Unlike a normal person would. And that saying anything other than how nMom is the best is viewed as persecution.
If I had siblings, I'd probably be NC with my parents a long time ago, but I'm all they've got and I moved 10 hours away, I have their only grandkids, so we've muddled through a relationship, albeit strained and distant, for years because my parents understood what my boundaries and, more or less, went along with them, up until my mom got sick and was hospitalized, during which time she and enDad totally forgot all the boundaries. I no longer have the energy to do all the work it took for us to be able to have a relationship, as I did all that emotional labor for them before I knew better, before I had kids, and before I developed stress-induced serious health problems of my own. Given my new circumstances, I'm no longer able to carry the burden of maintaining that relationship, and it's hard to find a way forward.
I feel for you. Just keep on reminding yourself that your boundaries are only requiring what normal healthy people would want.