It appears to me that your cat has a hair ball or something else causing a partial obstruction. This mass is too far down your cats digestive tract to come out her mouth but it is still making her nauseous. The best thing to do is purchase a product called Laxatone at the local pet store. Give your cat 1/4 inch of this paste every 4 hrs for the first day and then this same dose twice per day for 2 days. If your cat is feeling better, then we have moved this partial obstruction through your cats digestive tract and your cat will be fine. Keep your cat on a maintenance dose of Laxatone twice per week to prevent this from occurring again. If your cat is still vomiting, you will have to have your vet examine your cat to be sure we have not missed something. According to the symptoms you describe, this is likely to be the problem. Good Luck!!