I admit that I can come off as a really intense person - because I'm a hopeless perfectionist. Sometimes I may be unconsciously rude, so if I am too harsh on you, I apologize in advance.

Whoa, FF. We don't have that kind of grading system here, but it does sound really bad. o__o

Hmm...like you English isn't my native tongue. For me besides the dictionary (mostly I use it to check spelling and the meaning of words to make sure I don't use them wrongly), you can try reading books. Not just a few personal favorite books, but from as many different genres as you can. Study and take down notes on how the different writers write their stories and learn from there. Of course, keep practicing. :)