Since coming home from the nursing home my dad has been difficult. How can I deal with him?

my 86 year old father was just released from a nursing home. he was in the hospital and home for 4 months. about half that time, he was sedated. his mind is not right now. (he was admitted to the hospital for double pneumonia april 27th and just got out of rehab, oct 1st.) he is difficult and belligerent most of the time.he wants to get in and out of bed by himself and i know he will fall, making matters worse. we get into an argument about anything he is not supposed to do. how can i deal with him?