old67,
I'm sorry to hear that you are having to go through this. Gleason scores of 8 and 9 are not the best news, but by no means a death sentence either. A few things to think about:
Your PSA, at 4, is good news. It is my understanding (as a patient, not a Dr) that more PSA is released into the body as the cancer eats away at the prostate walls, therefore raising the PSA in the blood. A low PSA is a good sign that the cancer, whether aggressive or not, may well be in the early stages. It also sounds as if the cancer has not yet spread throughout the prostate.
My pre-op gleason was 7. My post-op (actual) was 6. Gleason scores are not always correct, and generally a subjective measure, depending on what lab tech is looking in the microscope.
There are others on this site who have experienced a similar diagnosis to yours, and you will receive a lot of replies from people who give you better answers than mine. We all, however, care about what happens to you and wish you the best in this tough situation.
Smokie