Have you left it alone in a tub with all your husbandry correct for a week yet. If you have than keep trying a little longer. Also maybe you can have your mom borrow you the money to go the vet and pay her back with payments or something. If not maybe you should find an experienced owner to take the snake off of your hands.

Also if you've really tried all the things people here have suggested in the past week chances are you've been stressing it alot trying to feed it everyday.