I agree with everyone else. Let them know you're afraid, then look away. It'll be in and out before you know it. I think the more you think and worry about it, the more anxiety you'll build up and you'll upset yourself more than if you were more calm.

Just think of how brave our fur babies are when they get theirs. If they can take it, so can you.

As far as the soreness goes, if you move your arm a lot after you receive the shot, it's supposed to minimize the soreness.