Best of luck David! Rudy's suggestion about the deep breath is also a very good one. I forgot about that. You want to kind do like you are going to pee when the scope is getting to that spot. It opens it up a bit and makes a big difference.
I've had an RC and they removed the prostate so I sometimes catheterize myself with a red rubber 16 french size catheter. I think that's actually bigger than the cystoscope and it doesn't hurt a bit. I couldn't have even imagined that before! It was one of the things I was really worried about when faced with the surgery
I sure didn't like it one bit before the surgery though!
However, the numbing gel DOES make a difference but be sure to have them wait 10 minutes after administering it so it can work its way down in there some.
That changes it from "HOLY CRAP!!!!" to about a "that's not very fun" on the comfort scale.
David, Mike is right it may seem a little odd to say, but it helps if you can just relax your stomach and abdominal area as they it that prostate portal, I found it helps to take in a breath and then slowly let it out as you try to relax.