Biopsy readings are subjective, and what looks like cancer to one person might look more normal or look like a different grade to another.
If you have not already done so, first thing to do is to have your biopsy slides sent for a 2nd reading by an expert pathologist: after that's been done to confirm where you stand, you can consider your options more fully and logically.
Everyone is different, but unfortunately most people including many doctors have thier pet theory about the best treatment option which they'll want to tell you about.
A good idea is to do your research on the various treatment options: the best comprehensive book I've read on this subject is the publication by Lee Nelson MD, "Prostate Cancer Prevention and Cure". It covers diagnosis, stages, lifestyle changes, diet, supplements, treatment options, selecting your doctor, etc.