From what you write, perhaps what is driving the decision for surgery as soon as possible is the finding that an entire lobe of the prostate is cancerous.
I agree with several other posters about
(1) waiting until the prostate heals from the post-biopsy inflammation--at least 6 weeks--before surgery.
(2) The perineal retropubic surgery is not done as commonly anymore, being replaced by the open retropubic surgery and the DaVinci robotic prostatectomy.
(3) It may be a good idea to let this diagnosis settle in and researching different options and getting 2nd opinions before deciding on which is the best for you in your situation.
In my own situation, I waited several months before deciding to go forward with surgery, but fully considered brachytherapy (a good treatment with excellent outcomes for many) and did some research on proton therapy (which was not practical for me).
You'll find a wealth of information, opinions, experience and help from folks who are at various stages of prostate cancer. I'm almost two years post-prostatectomy.
Take care and hang in there....Tim