I know your pain. Believe me I do. I've had my mother-in-law try to brainwash and destroy my wife for her own self interests. Mother -in-law is a life long cyclic alcoholic.
And there have been times that my wife has been confused and it rattled our marriage to the point of separation on more than one occasion.
After severals years of this I believe she (my wife) has come around and finally seen the light. Now her love and dedication for me is more than it has ever been in almost 8 years. I love and have devoted myself to her in the same manner.
I empathize with your tears your anger your la`ment.
And know the feeling of just giving up and telling yourself ultimatiums.
You do have control of your life and your life only. It's how you choose to act on it that will determine your day's months and years to come.