Turanil, I'll agree with everybody else here, your English is excellent, the only way I normally know that it's not your native language is the location you have listed on your profile.
On careful inspection, you don't use slang terms, and occasionally your exact choice of word or phrasing is awkward (but you have to be looking carefully to see that). For amateur fiction your command of the language is already better than a lot of net-published and fan written things I've read from native speakers. For professionally published fiction, you have a long way to go (but are on the way), but the professional line is a very high standard, as it is very competitive. Many people want to be professional authors.
Of course, good fiction writing is difficult in any language, even native speakers write junk, so become a good writer first. Practice, practice practice.