Correção de texto de uma amiga

Minha amiga me pediu para postar o texto dela, se puderem me ajudar a corrigir, agradeço.

Hello. I am sixteen-year-old girl. I have studied American English since two hundred eleven or thirteen, but unfortunately, I still make many mistakes. Becoming fluent in English is not my dream, but it would help me a lot. Sometimes I have serious problems with plural forms, adverbs, and the order of some words. I cannot surrender and be weak against these problems, which were already mentioned, I can face all of them without the help of people. There is nothing left to be done by me, unless studying and studying without any time for breathing or even living. Studying English may be an obsession, but it could be a worthy way of living without any life too. I am not tired enough to be stopping yet.