Butch Hartman pushes an idea that I agree with very much, as do many others in entertainment. Story comes first. Your art can look like Rembrandt, but if the story sucks, you're going to have trouble finding fans.
That said, don't get down on yourself. If you really, really, really want to be a better writer, there's only one solution. You've got to write. A lot. Every day. I looked over your artwork, and it's passable. It can work, but you've got to tell a good story. Writing is a difficult thing to learn outside of schooling, but there are resources available. Otherwise, you can put yourself as the illustrator and let someone else do the writing. Though, finding a good writer won't come free. There's a lot of documentation to go through if you're the concept creator.
First things first: Learn grammar. Spelling can be checked after the fact, and you can learn that through editing. You'll need to learn the basics like parts of speech and tense before you can move on to more intuitive things like metaphor and the nuances of dialogue. If you just want to stay the illustrator, then you've got to learn anatomy and life drawing.
