My kitten sick I need advice.. Read details?

I would take him to another vet and tell them of symptoms. If he's neutered he may have uti which is a blockage for his peepee. He may have problems with his food. Glucose shots were given? Does your cat have feline diabetes or hypoglycemia? If your cat does his blood sugar may be too low. Hell need to be monitored and tested and i believe hell need a high fiber diet. But take your records and cat to another vet maybe even take ur other kitty too. But take in separate carriers. Good luck. Hope he is well.