Here are some potential reasons for these symptoms:
* Gastrointestinal issues: This could be due to various factors like hairballs, food allergies, parasites, or even a more serious condition like inflammatory bowel disease.
* Diabetes: Cats with diabetes often experience increased thirst, hunger, and weight loss, which can lead to vomiting.
* Hyperthyroidism: This condition causes an overactive thyroid gland, leading to increased appetite, weight loss, and vomiting.
* Kidney disease: This can cause increased thirst, hunger, and vomiting.
* Other medical conditions: A variety of other medical conditions, such as pancreatitis, liver disease, and even cancer, can cause similar symptoms.
It's crucial to get your cat to a veterinarian for a proper diagnosis and treatment plan. Waiting could worsen the situation and potentially cause serious health problems.
Remember, I cannot offer medical advice. Please seek immediate professional help for your cat.