Nellie, you've had rotten luck. There are bigger PSA scores on here but not many. Your treatment is working, so hang in there. The combination of chemo and HT with luck will get your number down to single figures and you will look at life in a more positive light. The main advice I'd give is to get fit, no surplus pounds and maintain that healthy weight (hard to counter the lethargic effect of the HT, but it is doable), adopt a balanced diet ( what's good for your heart will help you fight the PCa)and go at life with a positive attitude.
As to the effects on your prostate, the cells killed off by the treatment will eventually be reabsorbed harmlessly by your body and expelled like any other dead tissue. If you're peeing too often, as the prostate is reduced in size by the treatment you should find this problem eases a lot. Eventually, your prostate will look more like a normal one, when scanned. It is probably mis-shapen and a bit leathery in places now, but this will change.
The Gleason score derives from tissue samples in the biopsy you had. You probably won't have another unless surgery is required at some future date, rather unlikely, I guess. So the Gleason Score is a measure of the aggressiveness of your PCa. In your case the number is not a big one. Mine was 4+5=9, for example. The surviving PCa, after I had my prostate and bladder out after five years showed a Gleason Score of 4+4=8, so it can change; it may vary through the tumour, I suppose.
Good Luck and remember the power of positive thinking!
AC