Inability to see consequences of ADD on relationship

I have been married for 18 yrs to an ADD spouse.  His ADD has gotten worse over the years.  The biggest things we struggle with are is general inattentiveness to the relationship, chronic lateness, clutter with all his belongings and inability to but anything where it belongs.  He seems incapable of seeing how these things negatively affect me and our household.  I'm always supposed to be the understanding wife.  I get very weary of it and stay stressed out much of the time.  It has gotten to the point that we are very testy with each other most of the time and always on the defensive.  It is a very unhealthy way to live.