Mother had a stroke. Joined my brother through a week of uncertainty of the outcome. She's in rehab making some of the nurses regret coming to work. I'm resolve in treating her with respect but this behavior isn't new to us. For five days she was kind, appreciative and cooperative, we were hoping this would be our transformed parent.
Sorry you're going through this. I already did, and my parents both passed away in 2008. Perhaps you are feeling numb because you are withdrawing to protect yourself ahead of her death.
Having a stroke not only fills one with fear and rage, but also destroys a lot of the "learned responses" of politeness and sets you back to the 2-year old level, emotionally.....intense response to simple things is a given.
I speak from experience here.
Talk with your Mom! I am sure she, like me, watches with horror at the responses she offers ............it will get better with time!