The best suggestion I can give you right now is without any delay take your cat to the vet. A cat ,when it falls sick tends to behave very much like a human. They began to sneeze; they also tend to have watery eyes. Cats have the tendency to sit very quiet in a corner. In case the cold is too much then the vet might give a shot of antibiotics. Or he or she may even suggest you to try and keep feeding the cat so that the cat doesn't have any kind of weakness. Try taking the cat in your arms and making it feel better, just the way your parents treat you when you are not keeping good.