Whenever I get a new idea, I always try to incorporate it into my story, Foreign Exchange. However, since you said that your own new ideas "cannot be added to the first story," I would try thinking of ideas that could be incorporated...and if not immediately, try to think of a way to twist the story down a path that will eventually lead to that new idea. Remember, it's your story, you can do absolutely whatever you want with it. Twist and bend it any which way. Make your ideas work. And as a last resort, if you simply cannot find a way to flow these new ideas into the original story, write a new story while continuing the original. You can write multiple stories at a time. This will take longer, and more effort, but at least this way you could use all of your thoughts. Hope that helps
