Am I understanding it correctly, that by "proton radiation, 5 treatments only" -- you mean no ADT? Regardless of whether your treatment was with ADT or not, I'm happy & wish to congratulate for your los PSA now.
I had SBRT photon radiation in mid-April, with ADT/Orgovyx from late March continuing for at least 8 months up to a year, oncologist daid.m. I noticed some mucus & blood in my stool for a few days post-SBRT. I suspect due to some healthy cells' damage due to no gel spacer between the prostate - rectal area, I'll never know.