For me, NC was the only option that allowed me to be true to myself and not feel guilty/ashamed/inadequate.
By maintaining contact, you maintain your position as a victim. You are expected to fulfill the role you always have had to take.
Your mum has no intention of changing or becoming the mum you properly deserved. Nothing you do or sacrifice, will make her that person.
I watched my sister die at 50 begging for the love she had always wanted/deserved from my parents. Something died in me with her, the hope that there would/could ever be the type of love I needed, love for who I actually was, not the role I was forced to play.
I went pretty much NC after that. Everyone told me I would regret it when she died, but I didn't really. Because there was nothing there for me.
I'm not blaming her, or him, I know that they had their own issues and did what they felt was right. But now that I am an adult, and have raised my own children differently, I can say with 100% certainty that they were wrong.
It is a very personal decision, but whatever you decide, decide it with your feet planted firmly on the ground. She will not give you the acknowledgement you crave or deserve. If she had that insight, she would seek you out and apologise.