Hi Benard
I also have APC spread to bones,I'm 3 months into enzalutamide and prostap 3 injections,I'm a bit younger than you but I did have symptoms similar to yours of having a spring in my step one day and can't be bothered on another.
It's not as bad now,hot flushes and sweats through the night now the normal niggles,aches and pains through the day but don't take any painkillers so can't complain with the condition I have.I began with a PSA of 2100 in march/april now at 0.478.
Hope this helps regards Phil