I'm happy to hear you've been inspired by the story to write for yourself, but I don't give permission for others to continue my stories.
At the very least, within the PDF you should have a disclaimer saying its not a continuation by the original author.
I didnt read the whole thing, just skimmed it, but it doesn't follow along at all the idea I had for the next chapters - and do note it's "chapter 1" so a "chapter 2" regardless of how long between release dates there is, it isn't a sequel, it's all part of the same story.
You've written quite a lot there so I'd say rejig some of the story to make it your own and publish it as your own work, and keep up the writing, but keep it to your stories, please. If you wish to write something as a spin-off from my stories, fair enough, but again, there should be a clear disclaimer its not my work and it's something you've done without my oversight or commission.