My Cat Is Loosing Weight Quickly And Is Showing Jaundice Symptoms, Need Advice ASAP!?

My cat is about 4 years in age. Since I have adopted her, she has not once had any major health issues. I have 2 other cats, and all 3 are indoor, on a very healthy diet, and see the vet for regular check ups. I began giving them canned food as a treat about 2 or 3 times a week. I had recently noticed that my 4 year old cat had been loosing weight...fast. I put together that she had stopped eating dry food all together, and only ate when I gave her the canned food. So I began giving it to her daily and monitored how much of it she would eat. In the past few days, she has barely been eating anything at all, she has lost more weight, and above her eyes, inside her ears, the lining of her eyes, and her lips are beginning to turn yellow. She is not looking herself, and i'm extremely worried. But, she is acting pretty normal. Sleeps during the day, stays up all night, plays with the other cats, ect. I called my vet this morning expecting to bring her in right away, but they can't get her in until first thing tomorrow morning. Like i said, she doesn't seem to be in any sort of pain, shes actually been more affectionate and she purrs as soon as i go near her. I guess I'm just looking for some good answers/info/tips. I also have to mention that I have been working at my local animal shelter for the past 5 months, in which i dealt with cats with contagious diseases such as FIP, FIV, leukemia, ect. But...I am as careful as possible, try to be clean and cautious. I remove my clothes as soon as I get home. But I am worried that i some how brought something home. Please help.