jehnifer,
I think I know how you are feeling. I am trying to not act codependant and trying to not judge my AH while still maintaining self respect. The self respect part is what I may have the most difficulty with. I can detach and but then what is the appropriate action when boundaries are crossed? You can't just pretend that nothing happened, so then what.
Here's my suggestion, although I'm new to this whole thing. Say what you have to say about the "issue" and say you accept(not agree) that RAH feels differently. If he acts angry, then remove yourself from the situation and focus on you.
I've really distanced myself from AH in last week(as much as possible when you live together). Of course, then I get accused of ignoring him. If he has something constructive or nice to say I will respond, but I am not pretending that everything's ok. One thing that has really helped me is practicing "mindfulness". It's about living in the moment and being aware of what you are feeling and what is happening "now". There are no wrong or right feelings, they are what they are. A great book is called' "Wherever you go, there you are." I would be honest about what you are feeling.
What to do after that, I would defer to the experts, as I could use some help, too.
<<hugs>> and Good Luck!