Backstory: My dad is completely blind. He's been so for the past 15 years, but has progressively been losing his sight for about 30 years. During that time he married my stepmom and moved to a different city, so I only saw him on weekends or vacations (my parents are divorced). My stepmom was his primary assistant/caregiver for 20 years. She recently passed away.
I would like to be as helpful as I can to my dad, but it seems to be a double edged sword. There are times when I ask if he needs help and he snaps at me for asking. Other times he gets angry when I don't offer help. He is, in general, fairly volatile due to his upbringing (his father was an abusive alcoholic), and I tend to shut down when he starts getting angry/yelling.
I just don't know how best to help because it seems like no matter what I do something wrong. Any advice is greatly appreciated.