Haig
I am sorry you are struggling with this. Uncertainty is not an easy thing to deal with. The first thing to remember is that until you have the results, you don't know anything for sure. The second is that you are in the system now and being looked after. What that means is that you will get the right treatment and the right time for whatever condition you are in. Statistically your odds are good as PCa is far less of a challenge than many cancers as a whole.
You need to remember that there are a whole series of curative treatments that start the game. The odds are good that you'll be down one of these paths and will "only" have a few scars and other side effects to remember this period by. Beyond that there are a whole host of treatments that can be used to follow up any early challenges.
The key is to get on top of things as much as you can physically and mentally (diet, sleep, exercise etc.). May I also suggest two things:
1) Seek out a qualified counsellor (ideally one who has cancer experience) to talk all this through. I suspect you will find they can help with your current fears and help you figure out why they are so intense. They will be able to help you develop coping strategies.
2) Get off the bl**dy internet! You are not alone in delving into the research to see what may lie ahead. The problem is that we are not medical professionals and it is proven fact (I found this out doing my thesis) that we over exaggerate things when doing our research. If you have questions, direct them to someone in the know, be that your medical professional or a PCUK/McMillan nurse.
You are in good hands in the NHS and they will do their nest for you. In the mean time, take it one day at a time and focus on your family - enjoy your time with them and enjoy Xmas.
Regards
PP