Sorry for another update, but here it is:
I was just really upset and expecting the worst, so I decided to go to bed so tomorrow's vet visit would come faster.
I fed the cats while Chance was still in his spot sleeping. Then I went down and fed the foster puppies and took my own dogs outside. When I came back in, Chance was sitting at the top of the stairs grooming himself. Thats the first time I've seen him do that this week so that is a good sign. I think (not positive) he had just been drinking because he was sitting by the water bowl. Then he went and started to eat. He's still eating now. I'm worried that I don't have the I/D food yet, but I'll get that tomorrow. If he keeps eating and holding it down though, do you think the food will be that bad for him? It is the food he's used to eating, but its kitten food so its really rich. He's not a year old yet so I haven't moved him to adult food. But since he's sick, is this going to make him worse?
(He just finished eating and is grooming himself again intead of plopping back down like usual!!!!!!!!!!)
*edit* He just drank a bunch!
*edit #2* He's back down again :(