lost file data

Figma file data is gone. It was fine until last November, but when I go in now, the data is rolled back to the state I was working in last June. The history back also goes back to June. I think there is a problem with the file. It is important data, so I really want to get it back. Can you tell me why?

(It looks like not only one file but the other two files were rolled back as well. I think there may be a problem with the account itself.)