Even though some things are very painful, no experience is wasted if we don't allow it to be. Maybe there is something new you are supposed to see or know about your relationship with your mum or yourself. Staying open to the possibilities, even though they hurt, helps us grow.

As an aside, my father (now deceased) sounds very much like your mum. I finally got to acceptance about who he was and I quit needing him to be someone he wasn't. I felt peace when I got to that point.