Hi Singa95,
I am in a very similar position to your dad, 50 and diagnosed 6 weeks ago with locally advanced PCa. Best advice I have been given is eat well, keep up the exercises (strength and cardio) and you will be eligible for more treatment options and cope better with any side effects.
My wife and kids have been amazing and supportive. After my initial diagnosis I was in shock, disbelief and angry, I am sure there will be a lot more ups and downs, but having my lovely family supporting me is what will keep me fighting this disease.