It would be really useful to have an accurate timeline including all your PSA test results, and each treatment starting and finishing. If you've had any Testosterone readings, include those too. (This should all be in your bio, not here.)
My first thought with the little info you have given is that this is a case which might benefit from 3 years on hormone therapy, but as I don't know when you finished the Zoladex, I don't know if that's still an option.