I also had a rapidly increasing PSA prior to surgery. It went from 3.1 in November 2005, to 3.9 in December, to 5.6 in May 2006. So mine was doubling about every 6 months.
From what I have read, the PSA velocity is something that is indicative of the aggressiveness of the cancer. But, it seems you have caught it at an early stage and you have selected the gold standard. My bible through all this is a book by Dr. Patrick Walsh, entitled "Guide to Surviving Prostate Cancer". It has a wealth of information in it which I have found to be incredibly helpful as I encounter the various issues and questions that have arisen in dealing with this thing.
Dr Walsh says that having PSA tests taken within a short period of time can be misleading as the differences in their readings could be a result of normal variations.
Another thing Dr Walsh says is "perineural invasion has no long-term impact on whether or not a man can be cured. For this reason, some noted pathologists have suggested that it should not even be commented on when found in a biopsy, becaues it's not worth worrying about".
You are doing everything you can and your biopsy results are not bad. If you have a partner, try to enjoy some quality sex prior to the surgery. I was out of commission for 11 months post surgery, not knowing whether it would come back or not. So, try to enjoy what you currently have. (One ironic thing for me is I started developing ED problems prior to surgery because I was worried about losing it post surgery.
Sorry I got off topic. I guess my point is that this is an ongoing situation. Try not to worry about the future and try to enjoy the present, which I know can be easier said then done.
Good luck with the surgery. I hope it goes well and your pathology report comes back with encouraging news.