Ability to separate person and symptoms


My partner of 20 years was diagnosed with grave ADD a year ago. Now I've tried to read about how couples can cope together. It seems to be important, in order to communicate honestly and avoid blaming the person with ADD, to separate person from symptoms. My partner, however, states he is incapable of making that distinction. This means he can't tolerate to be reminded of his ADD issues. Conversations about how to solve our (significant) relationship, financial and practical problems invariably end in painful emotional outbursts, and I'm at breaking point. His psychiatrist is currently trying out medication and it has rather made our situation worse. My partner has however regained ability to work and seems to do better away from me.
What can be done? Is there any way for my partner to separate his symptoms from his moral self and be able to address the symptoms calmly and rationally with me?