What's that thing Marie Kondo says? If it doesn't bring you joy, get rid of it? It sounds like this relationship is an obligation not something that brings value to your life. I'm not suggesting that people flippantly eschew long-term relationships/friendships, but maybe you would feel a sense of relief to get rid of something that was toxic to you (this friendship).

I have hung onto certain relationships for the sake of the length I'd been in them, and when I finally ended them I discovered how free and renewed I felt. And then sometimes those relationships can be rekindled when people do the healing they need to do on their own.

I don't believe that people are who they are at any age. Transformation can happen at any age for any person. But certainly it's not something to hold your breath for.

If you don't feel like you can confront her and have the conversation, then just end it. No need to put yourself through further pain. Life is too short to spend it trying to please other people.