We'll need a LOT more information.
What operating system are you running?
What folder were you sharing on your host?
What are the contents of the file you renamed? On macOS, you can find this out by opening Terminal.app and typing
and then dragging the file onto the terminal window and pressing enter. On Windows, you can use powershell or cmd.exe and do the same or a similar thing.
In all cases, it's good to have a backup solution in place. Both macOS and Windows 10 provide built-in solutions for transparent regular snapshotting and external backups.