Hi @irivesti, thanks for joining the Community!
I'm sorry to hear about the missing work. If the Dropbox account was full at the time you made the changes, then no edits would have been synced to the account online.
If this is the case, then you won't see any version history on the Dropbox site to recover the older version. However, it might be possible to recover the files from the local machine using a third party app or service to do so.
I'm sorry to be the bearer of bad news.