Won't eat since visiting the vet

Ever since going to the vet because she was vomiting, and being sedated for a blood test on Thursday, my cat has refused all food since Saturday evening. She's completely dazed, and it's as if she's lost her sense of smell. I went back to the vet on Tuesday; they gave her a steroid jab but they're adamant that nothing is wrong, suggesting she might just be a bit depressed. I'm really struggling to get her to eat; she refuses to open her mouth and just lies there all day. She's been like this ever since the anaesthesia. Myline was absolutely fine and full of life before her vet visit.