Confused

A couple announcements. Yes, I think I will keep writing in English, because it is way more easier to express myself and it will help me a bit to see my mistakes. Apparently my English teacher thinks I cannot write, well I don't know, I assume. I am trying so hard to write my assignments with full efforts, I get help from my ESL teacher, who by the way says my works are good, but I still keep getting poor marks, and I mean really poor. According to my English teachers given marks I don't know what I am doing. How so..? My last ESL teacher told me I could be a writer, that my writing is good, of course I need some improvements on my grammar and wording, but I have big opportunities to become one. And what I get in English class does not satisfy me, it is ruining me, my hopes, my thinking of that I am actually good, just I still need to learn; it does lower my efforts each time I get that small number on my work sheet... It might seem I am angry, that I dislike her, but I do not. I just don't understand why I get them, she does not properly explain me what I am doing wrong. And I hate that, because I need answers in order to get better. My other ESL teacher said I can be a writer, my present ESL teacher is saying I am good at writing, I get 100%, and my English teacher just gives me 50-60 in my assignments. It is incredibly confusing, because I depend on them, depend on what they are saying, and what they think about my writing. So how can I come up with a conclusion when there is so much different opinions. My minds are just so mixed up that I do not think normally, I was upset first, then I suddenly burst out with lough and now my eyes are filled with tears. I am just going insane, because my brain cannot absorb all of it. And I will probably just end up in mental hospital. Please help.