Last month of notes are gone are reinstalling windows (Onenote Windows 10)

Hello,

I'm using windows 10 and the built in one note app, rather than the desktop 2016 version. I had to reinstall windows 10, but it said that I wouldn't lose any files. I have checked online and all the cloud, but it appears that my notes from the last month are gone and they didn't sync - Some do seem to be there, but when I click them, it lists the onenote files as corrupt, and won't allow me to open them, and some aren't preset at all. I tried to check locally, but nothing seems to be stored, but all my notes were there right before I reinstalled windows.

How can I get them back?

Thanks.