Im same kind of person, for 2 years i ate , slept and drank my Mum's cancer to extend her life but it aged me massively, in my mid 60s, but if its who you are you won't change but yes try to get good quality food brought in . My food bill doubled cuz I bought all organic. The Dr said I " bought " my Mum 7 more months of life....it was worth it to me.
I know nothing of Prostrate Cancer but I see repeatedly how fasting starves cancer cells.
Dont want to give any false hope, but maybe check it out. Also I read some people do much better on treatment than others and its because their gut microbiology has 4 important bacteria strains...you can google them.
Wishing you luck....its a hard illness to watch in a loved one. My Mum was all i had, my hubby was passed at 57 yrs, so I dont regret a second.❤️