Understandable your worry; doesn't make it easier.
We have been traumatized by our PSA (AKA prostate specific anxiety).
In my case , I trust that the salvage radiation did its job and the ADT assisted.
And while I was very glad to complete the ADT portion of the treatment, I was worried every 3 mos thereafter whether the ADT effect had ended and would my PSA rise again.
Well my PSA remains undetectable 2 years after completing ADT.
And I hope for a long remission, but believe that there is continued and additional treatment available if/when I recurr.
And enjoy my current good health. That's the best I can do and that's a great gift.
Best wishes

You say in another message that your PSA dropped to .01. In this message, you say it went to .9. If your PSA is rising after surgery, while you are on ADT, Then you have become castrate resistant and need a second drug, but you’re already on it. Is your PSA rising even though you are on Elgard?

If it’s truly .9 now you must have a metastasis that is growing. Sounds like time for a PSMA pet scan to see what’s going on.

After surgery, my PSA stayed at < .1 for 3.5 years. I had salvage radiation and my PSA stayed undetectable for 2 1/2 years. Yours should stay that low after salvage radiation too.

This may just be a case where you need some Metastasis Zapped with SBRT radiation.