Hooray for Jack! Glad to hear he is out and about!
Judy, for males it is often barely even something they notice. They don;t need any pain pills -- they give them a pain injection at the time of dping the surgery and that covers them. It is a really tiny incision and heals really quickly. he will be himself probably about 12 hours after the surgery, once the anaesthetic otally wears off. My guys just slept a lot when they came home, and by evening I was having trouble keeping them from tearing around the house.
They are only swollen very shortly -- this can make it look like they weren;t neutered but it goes down very quickly. Within about three days the would will be healing fairly cleanly. You just need to make sure he doesn;t do anything that aggravates it or gets it dirty.
I promise you, he will be back to normal by the next day and you won;t need to do any special nursing of any kind. the only problem sometimes, is that some dogs will try to pull at the stitiches. My two just mostly licked them a lot, which is fine. If he looks like he's trying to pull them out they give you a collar for him or try the onesie route.