Chapter 2 Done...Chapter 3?

I decided to split up my original first chapter into three separate chapters. Chapter 1 was a breeze, Chapter 2 a bit of a struggle, and now I'm working on Chapter 3...which I'm having a hard time filling in at the moment as I don't have a picture of what it should be about. Hopefully, I can complete it by end of day tomorrow, so that I can correct intermittent portions in between so that the storyline flows.

An editor friend of mine told me that he breaks up the chapters into separate word documents. I am currently writing in one long flow. Does it matter? I'm not sure. For me, keeping all my chapters in one document helps me get a grasp on how long it is and what my goals are in completing it. However, it is getting rather confusing as the document becomes longer. I've been using bookmarks to quickly jump from one chapter to another, but it isn't perfect.