I hear you...sorry you feel the same as, well...most of us. I call prostate cancer the "Black Raven" that is sitting on my shoulder, and will be sitting there for the rest of my life...occasionally pecking at my head to remind me "I'm still here, and one day, I am going to kill you."
In many cases/types of cancer, you have the surgery to remove the tumor, and you can happily declare with much relief: "I am cancer-free". That is unfortunately "not" the case with prostate cancer. All of us who had our prostate removed, along with our two seminal vesicles and two vas deferens, would like to say: "I am now cancer-free", but we all know that a good percentage of us will see a biochemical recurrence (BCR) first, followed by more testing to see to what extent the presence of the cancer has grown back...and "where", after years of having no detectable PSA. We'll go through a PET Scan again at some point to see if there is enough PSA-producing prostate tissue present to take-up enough of the Gallium-68 tracer to be detected, so the urologist can say: "it is confined to your prostate bed", or "it is in your lymph nodes", " or worse..."it is in your bones."
The problem really is the pivotal surgical pathology examination of your surgically-removed prostate, that tells you whether your tumor started to spread outside the prostate having broken through the membranous tissue capsule that surrounds the prostate ("Extraprostatic Extension" or "EPE"). If/when that happens, all bets are off. Your pathology report will likely say that you have "surgical margins", which means that the entirety of the prostate and tissue removed from you, showed cancerous cells right up to the edge ("margin") of the tissue, meaning that it really extended beyond that, but was let in your body. How much and to where...who knows?
The only good news that I/we can hold onto, is that as my surgeon said: "like all cells, the cancer cells need blood supply to live and grow, and...I removed all of the blood supply that the could do that." But they still won't say "your cancer will never come back." If cancer cells survived by migrating/"crawling" (so to speak) to find blood supply before they died, then they just might have found that blood supply, and any hope you had to remain cancer-free, just flew out the window.
It amazes me to read of guys who had the radical prostatectomy 5, 10, or 15 years ago, and had undetectable PSA levels all that time, then they write a post here years later, that their PSA is rising and they found out the cancer has moved into their lymph nodes and/or bones...or perhaps is still confined to the prostate bed. "How" does that happen?
There are theories that prostate cancer (like other cancers), actually send out "scout cells" long before you are ever diagnosed. These scout cells just keep circulating and dividing/replicating to remain alive, and then after years and years, they "decide" to attach to a certain area and begin more establish growth that eventually causes the detectable rise in PSA. To me, a person with a Cellular/Molecular Biology degree, and a degree in Clinical Lab Science who was a Director of Clinical Pathology ("The Lab") for 20 years of my 38-year Laboratory career, it is just mind boggling. I wish you the best...trust in God and pray every day for guidance on how to live and manage your life...with that black raven on your shoulder.