Hi and welcome to YT
!
I totally understand your fears and where you're coming from, I feel/felt the same way. You should feel very good about the fact that you're doing pre-surg bloodwork as that will show you some reassurance that your kiddo is healthy and strong. As long as that bloodwork is good, he truly should do great under anesthesia!
My Marcel was neutered when he was 3 lbs and my Pfeiffer was spayed at that same weight, and they both did just amazing.
Just go forward, know your doing the right thing, and do your best to keep reassuring yourself that all will be well.