After I finally crossed the magical limit of 30k that seemed so unreachable for many days, the story has started to carry again. I decided to put names on the places, re-using some of the names I've already made up for this world in other stories. That probably messes up the geography big time, but for now it doesn't matter. Somehow naming the countries rather than referring to them as "the homeland" or "the city" helped make the story and places more real.
I've abandoned all attempts to write different versions or analyze the legend. Right now I'm simply writing down the main version. If I need more words at the end I'll fill in some analysis and other versions.
I've also abandoned my goal of 2000-word chapters. I switched to a new file after "chapter 13" had grown past 4000 words, but I didn't put a new chapter number or name on file 14. I'll fix the chapter numbers and all that afterwards, or if I need just a few more words to my wordcount.
Now 2000 words a day will make it. Unfortunately there are two days on which I won't have time to write much at all, so I'll have to make that 2741 words a day.