I'm thinking of my once strong relationship with my mom crumbling and I don't know how to deal with it
What do you think is causing your relationship with her to crumble?
I believe it's her excessive talking.
If your relationship with your mother is faltering because of an issue that you are having with her behavior, you should talk it out with her. Your mother won't change unless she knows how she is negatively affecting you. It's good to air out issues that come up between you and your family as it gives a chance for everyone to work on and resolve them.
I don't want to talk about it anymore.
I know it's difficult to bring up these issues. But, it you can't talk about the subject, there will ultimately be no resolution.