It's not exclusive to you. The more you put into something, the more proud and protective you become of it.

Should you make an RP with it? Absolutely not, haha. Roleplaying requires you to share stuff and be accepting of others. I have yet to see a fan RP that was entirely true to the source material, and all the players had the advantage of watching a show instead of reading some 150 page info dump. At this point you're probably better off shelving it for a book project later. Or just keep building on it, since it seems to be a process you enjoy.