Tommy although it all seems so fast I'm sure within a few hours you will find more than enough time to worry about everything that doesn't matter!
You are better off with this high speed response from diagnosis to surgery both from a mental point of view, worry never helped anyone to cope with anything :-?
From a medical point of view - once they find you have a cancer the sooner it is gone the better because do remember they are growing and although they may do no extra damage in 6 months they may bbe only a week or two away from invasion of a blood vessel or other tissue - never ever play the long game - the sooner it is dealt with the less damage it can do.
Well done to you for not putting off the checks a moment longer and well done to your urology team for prompt action.
Good luck and there is every hope of a positive outcome - just look at Elaine and she was the same size as you.
Keep us informed and just ask - we will help where we can. Most of us have been there done that and don't much like the TShirt! I guess you are in for the Trick or Treat of a life time! :-/