Thanks for all the lovely comments.
A quick update 3 weeks on from the op. I feel fantastic in pretty much every way. During week two I still had some pain in the groin area still where the spermatic cords were cut and retreated but that passed and I never took anything stronger than paracetamol. This week has been brilliant and I've been living normally, just as a female

I can't run for another 10 days or so but that's fine.
The biggest shock has been my libido. I expected it to disappear. The opposite has happened: I've had spontaneous erections and no issues at all. I don't want to be too graphic about it but, yes, I've also performed with my partner which I wasn't intending to happen so soon after the op but it did and it was more than fine. No issues whatsoever about functionality. Actually the orgasm was awesome: less focused on one spot and more whole body and intense, with clear liquid appearing. That bodes well for full SRS vaginoplasty, which I'm still soooooooo looking forward to having. Apologies if that's a little tmi but it might be of interest to those contemplating this route and for whom it's a slight worry. Still want the damned thing removed but I figure whilst it's still there ... and I now see it as something which will form my real new body self. After all, that 'thing' will help make my new clitoris so I look at it differently now. Yay.
The orchiectomy is one of the best decisions of my life.