Your snake may not eat until it feels comfortable and secure in an adequate environment. In spite of what your vet stated, some snakes have been known to starve themselves to death if they remain stressed. I would suggest that you keep trying to feed once a week with the same type of meal. If you can't find out what your snake has eaten in the past, your best bet would be to try a small live mouse or gerbil. Try to feed it about an hour after dark and try not to disturb your snake after you introduce the food. Also, do not handle your snake until it starts to eat for you.

Good luck!