My cat vomited and then would not eat or drink, breathes rapidly, and lies with its eyes open; it got an anti-vomit shot around 8:30 last night, first vomited a hairball, then yellow fluid

Hello, based on your description, this can be judged as hairball syndrome in the cat. When a cat has too many hairballs in its body, it usually shows vomiting of hairballs, and this irritates the intestines and causes vomiting of yellow fluid. In this situation, the owner can give the cat an appropriate amount of hairball paste to help it pass the hairballs. At the same time, use anti-inflammatory, anti-vomit, and acid-suppressant medication together to relieve gastrointestinal discomfort. If the cat’s symptoms do not improve after medication, take it to a veterinary hospital for further treatment promptly.