Brad,
Nothing to worry about. For mine there was no nurse, just the doctor. He injected a local anesthetic. He said there would be some pain from the needle which there was. After that it was pretty quick, and he explained each step such as cutting the vas, putting on clamps to close it off, etc. He didn't give me a prescription for pain and I didn't need anything. I did it on a Friday afternoon and took it easy over the weekend. There was a lot of purple skin for a couple of weeks afterward but it didn't hurt.
I got my wife to go with me - she's not at all squeamish - so that was a big help. I told the doc when I made the appointment that she was coming into the room with me and he was OK with that.
By the way, mine was a no-scalpel vasectomy so there was just a little hole and no stitches.
Good luck and don't worry about it.
KG