My advice is to use git to do the syncing, instead of dropbox. Also do not lose your files. Depending on how you loose them, you may recover them from your file system using some especial program to scan your file system and look for the deleted files. If you are lucky, your files was not overwritten yet. If not, then as you are using dropbox, it is supposed to be saved on your dropbox account.
If you deleted them and synced with dropbox, I think you have 30 days until dropbox delete the backups of your files for good/ever from the cloud. So you can access your dropbox account and check for the files you deleted.