My name is***** and I am sorry to hear that your cat's tongue is looking so strangely.
Just to confirm- the edges of the tongue are red and your kitty is very lethargic?
Also, do you have the spray that you put on her skin? Can you send the active ingredients or a picture of the label?
Based on your description, there are a few things that I would think of as causes for your kitty's problem-
-electrocution- does your kitty chew on electrical wires? This is a common injury in cats as they get zapped and burned on the tongue before the circuit breaker trips.
-chemical burn on tongue- this could be the spray, but it could also be a chemical that you used to clean your house. I have seen kitties walk through a chemical and lick it off and cause irritation in the mouth.
-toxin- there are several different medications and plants that can cause irritation in the mouth such as poinsettias, philodendron, etc.
-metabolic problem- acute kidney failure can cause ulcers on the tongue, drooling and lethargy, so that is something else to consider even in a young cat.
Please let me know what is in the spray so that I can help you figure out what is going on with your kitty.
Do the other possible causes also make sense? Do you have any other questions?