My cats sleep most of the day with occasional appearances lasting varying times. I think Rocky's 11, Buddy is 10, and Dottie is 9. I see them eat, but never see them use the litter boxes, but I don't have a studio apartment like you.

I'm so sorry that you spent all that money, and got nothing out of the visit.

Did the run any tests?
What did the vet say to you?