I lived it with my sister for over 20yrs... It’s a horrible thing to witness or be a part of...
As MM stated, the outcome is normally tragic when changes finally are implemented at this stage of the game..
Either you deal with it or roll the dice and force a major shake up and see what happens...
I don’t know any other way to lay it on the table for you Big D.
I’m truly sorry for your situation.
"Human footprints, I find, are always a disappointment in the wilderness, even when they are my own."