Great to see your PSA drop dramatically. I had Enzalutimide for eight months before it stopped working but can say, for me anyway, it was a walk in the park compared with Docetaxel.
Apart from the usual tiredness that all the treatment options for us seem to have, it seems to be much kinder on the body. The big one for me is that it is 4 (rather large) capsules per day, so no needles! No hair loss, no horrible taste in the mouth. So side effects are minimal.
As I said, I only had eight months on it but it did help having a lot more normal life, although the bar as to what constitutes "normal" is much lower now! It is a treatment option which was hard fought for, and I think it is one of the most expensive main stream treatments finally approved by NICE.
So embrace it and I hope you do well on it.