Given what you have shared, there is no way YOU can ever attain the ideal you have in your mind. Instead you deserve to be free of the weight she brings down on you and have some actual peace in your life.

I am sorry because from what you share of her it must have been hard on your children. I hope they get so they understand her behavior had and has nothing to do with them not being good enough. You all need to know that to the depths of you.