Coming from another angle , and I know this idea will just be dismissed unfortunately ,, however my advice for what it’s worth is to double make sure the silent killer isn’t at work in your body and get yourself a PSA blood test asap .
Lower unexplained back pain is one of the killers symptoms ,, NOT saying in your case it is , however so many men dismiss this as they have no other symptoms and when they do and go get tested eventually , in many cases it’s game over as it’s spread too far .
Good luck