What you are feeling is normal. I got nervous the days before taking my girls to be spayed. I was sure they would never be away from me or near a male. I was just sure something would go wrong or they would never forgive me.
However, I knew that the health benefits were important to consider and it was the right choice for us. In the end, everything was fine and they did amazing.
We have a male Am Staff and will be getting neutered ASAP. Good luck and try to relax, he will do great.