Hi,
I'm not sure how well briefed he was when he thought he'd have chemo. Now he's on hormones and could remain on them for a long time. Different people react differently as the disease adapts to the hormones. He may then be offered other hormones or go onto chemo and hormones.
There might be other treatments. They've put him on palliative so presumably there is no Radiotherapy except perhaps to ease bone metastasis at some stage maybe.
Without knowing his pre-hormone psa and rate of change and biopsy/MRI information about how far it's spread it's more difficult to focus information but he could still be around in 3, 5, 10 years in some cases.
You're right that writing things down can focus the mind. The initial impact is often a blur but settles especially when it seems things aren't changing. You can't ignore that it's there and things could change at the next blood test though. Let's hope for the best, Peter