Where is the line?

Hi. My wife has pmdd as a result of a stroke. We've been together 5 years. Her stroke was six months into dating, and the reason it happened is still somewhat of a mystery, leaning towards just a weak vein. I am extremely conflicted about so much, mostly, how much of myself am I supposed to disregard to allow for the illogical, the unreasonable, the memory lapses, the disrespect, the fighting? I am trying to maintain a standard of normality in the household, because if both of us are emotional to similar degrees than we will fail. But maintaining that wall has become incredibly tiring. I do not have things as bad as some here, of which I am both grateful and so sympathetic to those that do. She doesn't hit me, she can control some reactions, but the times she doesn't, or the times she doesn't respect my need or desire to NOT fight before, say, going to work for the day, or her blowing her gasket over what, in objective reality, is minor, is getting harder and harder. I can't leave her. I won't. She needs me, and I love her. But I see this relationship devolving into roommate status and I don't know how I can avoid that while still maintaining the ways I know best to navigate life without failure. I hope this makes sense to someone.