Is it correct?

Hello! I am Tat. I have been learning English language for 13 years already... I know, that it's a big period, but long time - 11 years of formal education was at school. You know how it's at school, Teachers don't really care, because pupils don't care.. So it is really hard to learn the language learning of English came after school. When Now that I am you're are an adult and you I understand that English the language better than before know... The However, the great biggest problem for me are is tenses.  , and... I always think that I speak very bad, My oral English is poor because my vocabluary is poor is limited, and my grammar is nothing atrocious.
Is this monologue correct?

Nothing wrong with your monolog except that it is not expressed fluently and smoothly as a native speaker.  I am truly surprised because Malaysia is used to be British Crown Colony!  So what happened?

Is this/this paragraph written it correctly?

Hello! I am My name is Tat. I have learned studied/been studying the English language for 13 years already. I know/realize/understand that it'sa big period it is a long/relatively long period of studying, but 11 years of it was at school [mandatory? pre-college/university?]. You should know/remember/recall how it's at school it was back then -- The teachers don't didn't really care, because the pupils don't didn't really care. So, the really hard/serious learning of English for me came after school [when you entered college? when you studied privately? when you paid for lessons?]. When you're an adult,  and you understand/recognize that knowing English is good for you/is of benefit to you/will help you, can help you. better know... The great biggest/worst/most difficult problem for me is tenses, and I always think that I speak very badly/poorly because my vocabluary vocabulary is poor/weak and my grammar is nothing almost/virtually non-existent.
Is this monologue correct? [Hello there!  Thanks for posting! It is well written and your ideas are easy to see, but as you, yourself, recognize in your final sentence, you need to improve your vocabulary which, in turn, will help you with your grammar. I, myself, am still learning English after many, many (too many!) years! LOL!]

Is it correct?

Hello! I am Tat. I have learned the English language 13 years already... I know, that it's a big period, but 11 years was at school. You know how it's it is at school, teachers don't care, because pupils don't care.. So really hard serious learning of English came after school. When you're an adult and you understand that you need to learn English. better know... The great problem for me is tenses, and... I always think that I speak very bad, because my vocabluary is poor, and my grammar is nothing.
Is this monologue correct?