My 2 year old cat has suddenly become very lethargic, and refuses to eat the food she has always eaten or drink her water. She vomited a white foamy substance with nothing solid in it twice so far. She has been using her litter box, but then returns to her bed to sleep. I poured some tuna water into her regular water which she drank a little of, and she has been trying to pick at the soft food I am giving her, but it seems to be difficult for her to eat it. She is trying, though. I am making a vet appointment for her but I have to wait until tomorrow and I just want to have an idea of what I'm dealing with or what I can do to help her!