My cat has been choking, coughing and sneezing constantly, HELP?

Bad breath is a sign that the cat is really sick. Throw in the coughing, sneezing and bloody mucus and you have a case of GET TO THE VET! It sounds like you already have an appointment, so I am glad to know you are taking this seriously. It could just be a nasty respiratory infection, or it could be something more serious, like lung cancer. I'm not trying to scare you, but this is why you want to get you kitty to the vet now.