I hope my own story can help to alleviate some of the worries weall have when diagnosed.
I had no symptoms and only found out after my physiotherapist did a PSA test to look at bone chemistry ( I have chronic back pain). The result was 8.9, which is double what it should be for my age (66).  My GP did a rectal exam and referred me to the Urology Dept.  They did an MRI, follwed up by biopsies.
Please, do not worry about having biopsies.  I had oral and IV antibiotics, then lay on my side. The rectal probe is only about as thick as your thumb. Just relex and let it in. Next was a local anaesthetic jab, which I hardly felt.  Then the dreaded biopy needles!  To be honest I didn't feel these at all.  You just hear the click as the biopy is taken.  I had 12 taken.  After that I came home.
The first 2 times I went for a pee, there was a bit of blood and it also appeared in my semen for a few days.  No pain, no discomfort.
I got my diagnosis a couple of weeks later.  In the meantime I had done a lot of reading and research.  A word of warning.... IGNORE all the American stuff.  They will tell you about many treatments available, but a lot of them are still experimental and not available here. Also, they just seem to be advertising themselves.
Next I met the surgeon who explained the results and told me that the cancer was on the left-hand side and totally contained, although right up to the margin. It was deemed too agressive to leave alone.  The options were robot-assisted surgery or radiotherapy/hormones.  I met and oncologist from the Christie hospital who told me that she would put me on 6-12 months of hormones, followed by 22 sessions of readiotherapy.  She ruled out Brachytherapy, which I would have liked.  I really didn't want the side-effects of hormones or external beam therapy, so decided there and then to have the surgery.
I must stress that the doctors I saw were careful to explain fully, their own treatments.
I had my surgery at Stepping Hill Hospital in Stockport on 2nd December 2016.  I think I was asleep for 5 hours.  I woke with 5 small wounds, a catheter, but no drain.  The only painkillers I had were paracetamol and ibuprofen.  I was allowed home the next afternoon.
The wounds were quite painful, but I had no pain inside for over a week.  Unfortunately my body didn't like having a catheter and I had painful spasms when my bladder tried to expel it, along with urine by-passing it.  I realise that not everyone has this but I wasn't warned.  The catheter and staples came out 12 days later ... such a relief.  After passing 3 urine samples and scans to show my bladder was emptying sufficiently, I came home, wearing a rather large pad in my pants!  The urology nurse gave me a bag full of information, pads, etc., from Prostate Cancer UK.
Now, 8 weeks later, I only have a tiny bit of stress incontinence. I have never wet myself and only use one thin pad a day.  I do not pee while asleep but do have to get up a couple of times to go to the bathroom.
I saw the surgeon this week, who told me that my PSA was 0.01, indicating that the cancer has gone.  There will be a follow-up in 6 weeks.  He also prescribed daily Viagra for a few weeks, along with a vacuum pump, to help get my erections back.
The message I would like to get across is that you should listen to the experts, do your own research and don't put off treatment, just because you are worried about the side-effects.  If I hadn't had the test, I wouldn't have known I had cancer and 5-10 years down the line it wouldn't have been curable.  I feel so lucky.