So sorry to hear that your dad has had to join our group. It is devastating news, I know. But once the diagnosis has properly sunk in, you will begin to realise that there is still a lot of living for your dad to do.
I was similarly diagnosed almost three years ago and I also was immediately put on to Degarelix. For some reason, I was not offered chemo at that time. I think it only became common practice after my diagnosis. My PSA dropped from 168 at diagnosis to 1.7 at its nadir. It lasted for 15 months, before my PSA started to rise again. I then went on to Abiraterone in conjunction with the Degarelix. My PSA started to drop dramatically again and this held for a further 10 months.
I believe, and perhaps someone more knowledgeable than me can confirm this, that early chemo (docetaxel) makes Degarelix work for longer, so your dad is on a good treatment plan.
I have had a round of late chemotherapy, which helped me for a while, but I am back to rising PSA again now. Even so, there are still further treatments I will be receiving in due course.
It is a long and rocky road, but with your help and the obvious love you have for your dad, he will thrive I am sure.
As a number of people on this forum pointed out to me three years ago, incurable does not mean terminal.
Best wishes
Peter