Did family and house stuff all weekend. Today I wrote in-...

Did family and house stuff all weekend. Today I wrote in-scene backstory about one of the characters in the swordfighting ms. I'm wondering what will happen if I keep going in this direction--will I get loads of backstory written about everybody, then have a bazillion pages I still don't know what to do with? How is doing this going to help me figure out how to structure the story?

It feels like I'm at a plateau--like when you're trying to lose weight, or trying to exercise at a certain level,...