Bean is being desexed in about 5 weeks and I'm scared too but I figure the risk factor is pretty low and I'm sure for my vet it is a routine procedure. I know I will be a nervous wreck on the day but I know it is what is best for Bean.
Pam, do you have the pre-op bloodwork done before neutering? I didn't get it for Charlie a few months ago nor for my last two dogs 15 years ago when they were neutered but II have had closed to 100 animals in my life. I rescue and rehome a lot of them, and everyone is spayed or neutered before they leave my house. I have had exactly one complication, Reggie had a retained testicle and his incision got infected, a little antibiotics and he is fine. None had a reaction from the anesthesia. I hope ths helps ease your mnd a bit.