Hi Junpoy,
Believe me, in the internet world, grammar doesn't matter much (You have to be coherent though).
Speak to your readers in a way where they could relate to you, if the content is exciting then grammar wouldn't matter much.
Use MS Word to correct your writing, read a lot of books and i think you should be OK.
I can see that you already do have what it takes.
Wish you luck and success,
KnowledgeFirst