The animal should be fed something that is approximately the width of the widest part of the snake. I, however doubt he will eat in that condition and it may not be a good idea anyway until that spilt is closed. There are things that could be done but you do not have the experience right now to do them. I good vet is going to be able to help you and safely get the animal nourished so it can hopefully recover. It is going to take work on your part though. Make sure you are mentally and financially prepared to do what needs done. If not, I hate to say this, but it may be better to euthanize the animal.