Hi Liger'smane!
I've never seen you here before. I noticed this thread had no replies and I know when you have something to share it's very disheartening when no one replies. So here I am.
In answer to your question: I don't know how much help I could be. I'm working on two other projects right now, and there goes my free time. However, if you'd like to bounce your idea off of me I would definitely give you my two cents. It might help organize your thoughts on this story, since you say you need help writing it.
I really think you can probably do this on your own and just need a little guidance.
Anyway, I think you're very talented at 13-years-old. I'm glad you're stepping out and paneling and practicing your manga skills. Most people say they want to do manga, but rarely leave the comfort of concept art and actually try to panel. I mean you, wow o_o, you've stepped out and even tried dialogue. Is that all hand-written? That must have been very difficult.
Anyway, share a little more of what you're looking for and the story you have thus far. Also, how many pages have you already drawn and do you know where your story is going; such as, the ending? ^___^
Hope you the best. ^__^