First, thank you to those of you who wrote me with backup suggestions.
I've implemented some of them and am generally planning to do backups more often, both automated and manual.
Next, I've rebuilt maybe 70% of what I've lost so far. I think there are three main sections I haven't rewritten yet: one is 2/3 rebuilt as of today, one I haven't had time to rewrite and one I just haven't been able to remember. I know I did something with a specific character, but can't remember exactly what or where. I'm still hopeful that it will come back to me at some point in editing.
If the sizes of the corrupted files stayed the same after the system crash, then I lost 34kb of text, which is about the size of Rei's introductory chapter.
I don't think I'm going to have much time to write this week, but theoretically next week should be more open.