Michael,
This stage of diagnosis is very anxious - sorry you are going through it.
You haven't be diagnosed with prostate cancer as yet. Prostate cancer is almost never painful in the way you describe.
Secondly, your symptoms are in my view pretty much a perfect match for prostatitis, which generates referred pain in testicles and tip of penis, and other areas of the abdomen and rectum. (This is because your brain has no sense of pain in the prostate, so it refers prostate pain to other nearby organs.)
There's no way I can assure you it's not prostate cancer, but I would say it's far from obvious. You will just have to wait until the diagnosis is complete until you know though. The next step will be a prostate biopsy, and it is this which can diagnose prostate cancer.
I'm afraid GP's know rather little about prostates, but it is good that you have been referred, and this should get to the bottom of it.
If it is prostatitis, getting that treated can be a problem, because not only do GP's not know how to, many urologists don't either. We can talk about this if you get to this point.
Here's wishing you don't have prostate cancer.