"When I last tried to feed him a few days ago ... he bit me when I reached in"

How exactly did this happen? Were you holding the "prey" in your hand? Had you already presented the "prey" to the snake? Had you handled the mouse in your hand that got bit? He hunts by smell and heat signature. If he already could smell the mouse, and then sensed the heat from your hand, it could very well have been a feeding response.

I generally try not to touch a mouse/rat (or even my dog) when I'm feeding or working with my snakes. I use forceps (hemostats) to pick up and present the prey. Keeps my hands free of rodent scent and well away from a potentially hungry snake. I also keep a bottle of hand sanitizer near my snakes' enclosures. If I do get mouse/rat scent on my hands, I'll use the sanitizer to remove the scent.

Steve