He’s just throwing up like a lime green color and won’t eat anything at all
I'm really sorry to hear that Merf is experiencing these symptoms. Given that he has been vomiting multiple times a day for two days and is also experiencing diarrhea and loss of appetite, this situation is quite serious.
There are a few possible causes for these symptoms, including gastrointestinal upset or obstruction, ingestion of a toxic substance or foreign object, infections or parasites, and issues with the liver or pancreas.
The green color might indicate bile, which can occur when the stomach is empty, or it could be something Merf ingested.
Lack of appetite is a very non-specific symptom that can occur in wide range of diseases, so diagnostic tests chosen by a veterinarian who checked him directly are necessary to identify the cause.
And, even if cats do not eat for at least 48 hours, they will develop fatal liver damage (hepatic lipidosis). So, if he hasn't eaten in two days, it's important to re-establish his appetite, but veterinarian treatment must be done for the two days of anorexia. As a result, please take him to the veterinarian as soon as possible.
At home, you can try to ensure Merf has access to fresh water to prevent dehydration.
If you have any further questions, please feel free to ask. Thank you.