My 15 year old cat went to the vet 3 days ago to have a check up on why he was eating normally, but was losing weight. We had him tested for a hyperthyroid and diabetes, but he had neither. The day after he came back form the vet he has spent all his time in the basement and does not come up to eat. He has not eaten in 3 days. When we try to give him food he smells it and runs back to the basement and vomit. Does anyone have any suggestions for me before i can get him to the vet?