Think of it this way, Rebecca. You are doing your boy a favor. Seriously. An animal's instinct (all animals) and DRIVE is to reproduce to keep the species going. When a pet is kept away from being able to do that, it truly is cruel. That is what they live to do..keep the species living.
If we are not going to let them act on that drive..satisfy that drive, then we darn sure better love them enough to take that drive away so they are not being "held back" and deprived of all they know in their DNA - which is go make more babies/species members.
Neutering is actually the most humane thing one can do for a male pet. So, you are loving your baby enough to overcome your fears and help him. I know it's hard because of surgery risks and he's such a little thing, but it's worth the risk to put his "drive" at ease.