What I struggle with most, is where does the mental illness end, and the a$$hole begin?
What does it matter? You're with someone who sounds incapable of having a healthy relationship. You're unhappy in the relationship. It's really about you -- stay in a hopeless situation or leave and deal with your own issues. I recommend Alanon because it kept me sane, helped me realize I'm powerless over other people and their problems and let me to a good life I value.