My Dad was diagnosed with Prostrate Cancer 2 years ago.
He was in his early 60's.He like your father, ached alot , lost weight and was very tired.
He was able to go private through his work, which speeded up his treatment, although his main treatment was done though the NHS as all prostrate cancer treatment is done though the NHS.
After all the scans etc he was advised to have Brachytherapy - this is where they implant radioactive 'Seeds' into the prostrate.
Due to other health problems his operation wasn't done straight away and he had to have hormone injections into his stomach for 2 months, this stops the testosterone making the tumours grow.
The operation went smoothly, and obviously Dad had quite a bit discomfort , as well as waterwork problems for a couple of months. They do give medication to help with this, but I know the waterwork bothered my dad alot. I was living with them at the time, and was at home with him whilst he recuperated, and witnessed how humilated and embarrassed the incontinence made him.
He was off work for a couple of months, and obviously had to have regular check ups to his PSA levels etc.
I also know that it bothered my Dad , that my children couldn't give him a cuddle/sit on his lap for the first few months, due to the radioactiveness of the seeds. Although that does wear off after about 6- months to a year.
My Dad had his last check up in May and they have said he only needs to go for yearly appointments now.
Prostrate cancer found early is easily treatable.
Good Luck to you all, it can be very worrying for everyone, especially when the diagnosis has just been made.