My 86 year old mom was recently diagnosed with dementia following a pretty bad UTI. Her behavior has gotten worse as the weeks have gone by. She has horrible delusions about my dad; he's an impostor and wants to cause her harm. This causes her to act out in truly mean ways. For example: spitting and slapping at him. Before all of this, she was the sweetest lady. I'm at a loss, and really hurting for both my parents, and I just don't know what to do. She also refuses to take food, water or medicine that he offers her. He's her only caregiver at night (sitter during the day). We were hoping that being at home would clear up some of the confusion, but it's just not helping at all. Any advice?