Snakes have a remarkable way of healing themselves. The best medicine is usually keeping their environment in ideal conditions and leaving them alone. At the condition that your little guy is in, you may be better off contacting the help of a local experienced keeper. This vet is obviously doing more harm than good. I have yet to meet a vet that knew more about how to care for reptiles than your average enthusiast. I hope your little guy pulls through, he is a beauty