What do I do with my story?

Your post is well written. I am not disappointed by the standard of punctuation or spelling, and I was interested in what you have told us about the conceptual evolution of your story.

That all bodes well for the prospect of a successful book.

You have put more than enough time into thinking about it, and I really do think it is now time for you to get something written down, no matter how little, on a regular basis.
I suggest you aim to spend at least one hour per day, five days a week, writing your book and keep it up until it is finished to your own satisfaction.

It sounds like you have a very clear idea about the story-line with adequately detailed outlines for your characters. This indicates that you could easily write the parts that are of greatest interest to you first, regardless of whereabouts they might eventually appear in the book. Such a strategy will ensure that you have maximum enthusiasm initially, thus making it easier to create an encouraging amount of typescript, each time you set about the task.

When you have composed a reasonable quantity of really interesting text, it should then be relatively easy to link it all together to create a coherent book.

I wish you good luck with your project. I am confident that you will find it very rewarding intellectually and, with a little bit of luck, financially as well.