I tried replying to this yesterday but my computer messed up.
Like others have been saying, make sure you keep him on non particle substrate like paper towel. Wash the wound daily and use the non sting/non scented neo sporin to help fight off possible infection. He is going to shed A LOT to try fixing that wound. If he is eating still then I think that he will recover and be fine. Babies are resilient, they're born to survive.

I rescued a garter snake that had been hit by a lawn mower, she was almost dead when I found her but I cleaned her up and warmed her up and she started eating and was on her way to the park after a few week.

Thanks for taking the time to save him when so many others would have given up