Is it possible to have alcoholic fatty liver at age of 19, drinking since 2 years large amounts (4 liters of beer/0.3-0.5l of vodka) once a week?

Watch for cirrhosis: Alcoholic hepatitis would be more the concern. Your liver is an amazing organ in that it has the ability to regenerate. However, organs have finite reserves and once you have cirrhosis, there are too many complications to mention. Seek help such as aa or tell a friend. Otherwise life will be short and full of medical complications at a young age.