Learned my lesson years ago
I gave up using the default file save location and went to using per project folders. This keeps each song and ALL files in a separate location including all used/unused/deleted wave and MIDI files txt files etc.
I have a laptop and a desktop computer which I use interchangeably and all song files are on both computers so I immediately have an in-house backup in case one computer fails.
Every Saturday morning I use Acronis backup software to do an image backup of my entire disk on each computer and these are kept on separate USB drives.
On the desktop , all my song files are On a separate drive D: and in addition to the image backups previously described I also do a copy-replace of all the songs I am currently working on. These are kept on a separate USB drive.
In most songs, I make multiple corrections changes etc. and I use what others have suggested, doing a file-save as when the song is completed so that unused files are not saved. I do keep a copy of the original folder for about two weeks until I'm sure I'm no longer going to need the unused files.
I hope you can find all/some of your files but strongly suggest using per folder savings and an external backup.
Fred