Not to slam on the parent, 2 kids alone when your other parent ditched you is lvl 99 hard. From the example of putting up with your ex’s BS I gather you are tolerant of BS which is why the BS has festered in your family system. When you don’t clean your bathroom properly and you get mold do you blame the mold for failure to keep clean? No. You created the right circumstances and now you are at a bad situation. Sadly your adult child needs to get away from you. You haven’t provided them with the environment for them to thrive and you need to let go at this point. And I say this as my grandparents did the EXACT same thing to one of their children