My uncle (91) has stage IV prostate cancer with no pain. Should I call hospice?

My 91 year uncle was diagnosed 2 years ago with stage IV prostate cancer with bone met. He has been on Zytiga with prednisone that quit working about 6 months ago. He was than placed on Xtandi , which brought his PSA level down from 106 to 90.
He also has AFIB , COPD and is on oxygen. Three weeks ago I saw a decline in his health. He was sleeping a lot , felt nauseous, headaches, nosebleeds, and started to become very weak. He uses a walker with is almost impossible for him to get up and use the bathroom 15 feet away. He was having trouble urinating so off to the urologist. All test came back negative for UTI or bladder infection. Nothing was done. 2 days later he was feeling worse.He was very weak, not eating, had a yellow tinge to his face and had incontinence I was told to call my GP. I told him his symptoms and that he had a yellow tinge to his face. He had taken a fall too.He also had a lot of back pain near the kidney area. The Gp told me to take him to the ER. I told the ER Dr what was going on and he asked " so what did you bring him for?" I almost grabbed my uncle and left! I couldn't believe what I was hearing! I said ALL OF THE STUFF I JUST TOLD YOU! My uncle's oncologist was out of town for the holidays or I would have taken him there! They took blood, but refused to do an iron test ( my uncle's iron levels have caused him to be sick before) after a CT scan on his head and trying to get him to urinate , after a full bag of saline , he urinated about 1 cc. Well the assistant nurse tipped it over and that left a small amount to test. They tried to put a catheter in and only got 1/8 " in. So off to his urologist 30 miles away. He finally got a a catheter in, but he had to open the end of his penis with forceps.
Oncologist came back and we went yesterday. I told him everything my uncle has been experiencing and he recommended hospice. He told my uncle he was dieing. My uncle has very little pain but he is weak in the legs. It is hard for him to walk. Urologist appt coming up Friday and I am torn on calling hospice! I am his 24/7 care giver. I sleep in a recliner only 6 feet away from his bed and I never leave him unattended. I am always home. I might be doing the dishes but he is never alone. I'm really not sure if hospice is needed at this time? Any past experiences would be greatly appreciated!
He has never had Chemo. The Dr said at his age it would ruin the quality of life he has left. I really don't want to see him on morphine, if it is not needed at this time because he is NOT in a lot of pain. It is very minimal. I'm trying to do what's best for him. He told me he doesn't feel like he's dying, he's just weak. The oncologist says this is not a side effect of Xtandi. This is a very tough decision for me to make. I don't know what to do.
I can't lift him to much because of my own health problems. Numerous back surgeries. His spirits seem to be okay today and his eating has slowed down but he eats. He has not given up.
Please advise, I don't know what to expect next. Thank you and God Bless.