I recently became a CNA and my instructor was a nurse specializing in Alzheimers in nursing homes, and my good friend's mother has it too. They both said fear is a big part of the disease. Fear and emotional distress, because the person is still in there and altho they are more comfortable with their own reality, they know things are not right or normal, and it scares them. I would be, too. I'm sorry you're going through this, but if you can be strong and patient with her it will probably turn you into a special and amazing person.