Sorry to read about your journey and your current situation, on the flip side things don't seem quite as bad as you might have first feared (I think?), although the failure with the original RT is, of course, a major disappointment.
Your story and original diagnosis are similar to mine (cT2c, MRI T3bN0Mo, Gleason 4+3, PSA 27.9), although your subsequent treatment differed as I had 7.5 wks of RT following 8 months of Casodex.
I am in a similar situation with a failure some 9 yrs after my original journey started in 2010 with a PSA reading of 12.8 taken in Nov last year (interestingly it has subsequently risen to 13.2 since).
Bone scans, MRI & PET scan thankfully show no spread outside the Prostate but a recurrence of T3b with two areas one in the Prostate & the other in the left seminal vesicle (sounds like a contradiction but that's how the Urologist described it, RE spread outside the Prostate.)
PS: I sympathise and empathise RE: HT, it sucks!
Anyway I don't want to derail the thread so I will be following with interest and lets hope things turn out in a positive way, all the best