Been diagnosed with fatty liver so is this not serious?

It can be.: Although in most people fatty liver does not progress, in some people it can go on to develop worse liver disease, and a few people will eventually develop cirrhosis of the liver, resulting in either liver failure or the need for a liver transplant. For now, you should keep close tabs on it with your liver doctor, and it is important to try to lose weight and curtail alcohol use. Good luck.