How can Gary eat again?

Question
Dear Dave or David St,
How can I make the poor Gary eat again and make the black spots on his shell to go away?
I want Gary to eat again and the black spots to go away.
Please give me the bestest instructions of how to take care of Gary.
I don't really know how to take care of bottom feeders cause Gary is my first bottom feeder and I am justa kiddo.
Sincerely,
Samuel and SICK GARY

Answer
keep the tank temperature under 78 degrees, offer him food he will eat, and keep his environment clean... snails do not have a long life span... I can not help you with Gary because I do not have enough information about him or his tank conditions... dave