The hardest thing for any one is caring for a family member, there is history there and it can cause so many emotional set backs for both the care giver and the patient. I hate that you are having this trouble. Maybe you could find a mediator to help you and your dad navigate this time that he is so angry. Unless he has dementia which can really cause so many mood swings and problems. Good luck and I hope you and your father can get to a good place together.