It is a strange dilemma.
If your testosterone recovers naturally as is intended, it may give you PCa recurrence.
However, if it doesn't recover, you can't have testosterone supplements, because it may give you PCa recurrence.
I'm not sure if there's any direct correlation, but given how drastically my testicles have shrunk on HT (by 60% volume last time I measured, and still shrinking fast), I'm not hopeful I will ever get testosterone back naturally after HT. Would be interested to hear from others if they got testosterone back after such shrinkage.
As for tiredness - I haven't noticed any yet, but I am doing lots of exercise to try and keep my body in shape.