Thank you for sharing this, it's something I can relate to.
My relationship with my mother (subject of post in another forum) has degenerated because I won't do something that goes against a basic moral code. Years ago I would have acceded to her wishes and apologised for this event that has caused a family rift.
Just because her mother allegedly ruined her self-esteem, it does not give her a free hand to mistreat me mentally. I've worked hard and continue to, trying not to be consumed by these negative traits. An ex-partner and ex-colleague years ago said I should get out of this toxic relationship How I wish I had had the strength then to do what I've done now. Next few days/weeks or even months are going to be difficult, but at 65 enough is enough.
As an adult, whatever your age, it's not your responsibility when others mistreat you, it's solely theirs is an ethos I totally uphold.