Yep, he's not nearly as far gone as I feared when I started reading. You can relax and concentrate on getting him treated for the RI. Remember that generally when they're on antibiotics, they won't eat.

If you have a experianced reptile vet, you can ask that he tube feed some of that slurry stuff while he's in for the exam. If the vet thinks it's okay, that could help a little bit while he's on more antibiotics for the RI(or whatever he's diagnosed with).

Good luck. Also, could you post what enclosure you've got him in? Maybe folks can suggest changes specifically for a stressed ill snake to make it better, even though you seem to be a knowledgable keeper? There's a lot of tricks and tips out there.