Kitten sick with Uri. Breathing through mouth and severely congested.?

My3 month old kitten was diagnosed with a URI on Monday, for sneezing and clear runny runny eyes. They prescribed Amoxicilin drops and gave a shot of antibiotics. However, by Wednesday, she was coughing and by Thursday, wheezing. We took her back on Friday, and she got another shot of antibiotics AND a shot of steroids, to help her open her nasal and sinus pages, so she didnt have to struggle to breathe. We bough a humidifier and have been letting it run in the bedroom (with her in it) ever since. Friday night and ALL DAY Saturday she ate like a champ and slept most of the day. Her breathing was great. However, we woke up this morning (Sunday of course, so no clinics are open) and she's as bad as she was Weds and Thurs. She can't sleep, keeps bobbing her head and refusing to lay down, and shes so tired that she wont eat. I know the vet cant keep giving her steroids, but I dont know what to do to help her. The humidifier is still going, she's still drinking water, but she wont sleep and she cat eat. She's so congested and its hard for her to breathe again. Please tell me what I can do to make her feel better.