I'm not trying to sound like I turned into some kind of wise man, but it's nice to realize that your little pocket of the world isn't the whole world.
In writing a series of stories about the same characters, plan the whole series in advance in some detail, to avoid contradictions and inconsistencies.
Then, with lots of people doing that without ever looking over their shoulders to see how they were affecting anybody else, it couldn't work, and it didn't work, and it just came to a standstill.