Oh God, OP, sounds so hard. I really feel for you.
I am going to tell you my story - obviously everyone is different and I not remotely suggesting what happened for me would work for most people. But for me, NC with my mother for a period of time was actually a stepping stone to us achieving the better, healthier relationship with each other, which we now enjoy. I suspect I may be very rare in this - but, for what it’s worth.......
I had a terrible relationship with my mother, (think Narcissitic mother type behaviour etc) and after LC for a while we went NC with each other (it was kind of both our choice in the end). Now, what actually then happened during this time of NC was that we both did some inner work - counselling, worked on our MH etc (totally separately and entirely coincidentally). After quite a long time, we agreed to try contact again and actually we found our relationship was better than it ever was before. We somehow managed to avoid all recriminations (we had both learnt to avoid “you” statements and leave the past in the past), which meant there was a path to an actual relationship going forwards. Not a super close one maybe (I certainly don’t tell her everything, as she used to want me to), but friendly and positive - we do have lots of things in common (books, politics, sense of humour.....) and get on perhaps mainly because of those now.
I wouldn’t like to say exactly what changed for her (as I say, we are still not THAT close) - for me, I had definitely, through counselling and space, come to realise that, though my childhood was far from perfect, and she would certainly never be the idealised mother I wanted her to be, I was able to forgive, move on, and just finally accept her for who she is.
I would say it feels perhaps more like a friendship than a mother/daughter thing now. But that means all the controlling stuff and the guilt stuff is gone, so I am fine with that! And I DO love her. Just not in the way I always wanted/felt obliged to.