The first thing you should do is not use emoticons or mix question marks and exclamation marks! Both are actually common in informal communication these days, but as a teacher it's best to try to teach standard English. Of course, I have no way of knowing whether this story is true or just a language learning exercise. Your English isn't at all bad here, and is quite understandable. "No enough" should have been "Not enough", but that's a minor issue in terms of how understandable the text is. "So", as you are using it here, is a conjunction and should really be used to connect two parts of a single sentence rather than to start a new one. That said, it's not uncommon for people to start sentences with "So" these days, but it's usually done for literary effect. Also, even if you start a sentence with "So" it is usually carrying on an idea from a previous sentence. In the case of the last sentence "Let's be friends" does not really flow naturally from the previous sentence; it's a separate idea. Finally, I changed "others" to "others' "; the possessive apostrophe is shorthand for "something that belongs to others", in this case English skills. However until you become confident with handling possessive apostrophes (something that still confuses many native English speakers) it may be best to avoid them. You could also have said it as "My English is perhaps better than that of the other teachers". It means the same thing but you don't have to worry about which side of the "s" the apostrophe goes on.

Hei, wanna chat with me? ;)