It wasn't all very conscious, Ami.
But a pivotal moment, even though I struggled with a lot of guilt about it, was when my mother was manipulating me by "calling in my brother" and had him tearing down the interstate from hundreds of miles away...and I realized it was all because I had said NO to her. NO I will not stay home and become Cinderella. I will give you a tray and comforts and be sure you are safe and well tended, and then I am going to see a friend. She woke up from a nap that day and I had covered ALL the bases, and left a note and everything she needed. But she had not wanted me to go out and she was PISSED (because she was no longer in control).
When I got home 2 hours later and realized what sort of drama she'd engineered (she knew how vulnerable I have felt about my bully N brother) -- I blew my stack. I said if you don't call him and make him turn around and go home right now, I am moving OUT. And I meant it.
Thou Shalt Not Blow Thy Stack was the 11th commandment. But in the last 9 years I've gotten angry at her twice, and it cleared out a lot of sludge. After the explosion (and I WAS sorry for the explosion, because I was so angry one time I had her literally shaking) -- I realized how seriously toxic the situation was and I think she did too.
I got back into my own shoes.
The way I relate to her now is always courteous and friendly, sometimes with some humor. But most of the time, there's no intimacy. She's comfortable (that's her norm) and I am no longer missing or yearning for intimacy with her. So a polite I'm-in-charge-of-arranging-your-wellbeing kind of relationship is what we have now, and it's peaceful. She no longer tries to get further obedience (doesn't boss me around much, and when she tries, i just say yes. No. I'll do it later. I'm not going to do that. Sure, I can do this. You're welcome. I'm glad. Sleep well, g'night. -- that's about our daily dialogue. I forgot: Here are your pills.) I'm not hostile at all, smile at her often, we share little jokes. I feel compassionate, just not close or especially interested -- old self-absorption by an N-ish person is DULL. I love her, but it's a detached and comfortable love, and has no drama in it.
Hope that helps, Ami. Best I can do. (I have noticed how much more peaceful and appreciative she seems to have become, so perhaps some of the grasping agony of being a histrionic-Nish person has faded for her. I'm glad.)
Hops