Do you have a backup system? It is a really good idea, especially if you are an AutoCAD/Autodesk Product user. I work with customers quite often who have had files become corrupt. Sometimes those files can be recovered and saved; sometimes they can’t. Without a backup system, if corrupt files cannot be repaired, then those files can be lost and potentially hours and hours of work are lost. That’s where a backup system becomes essential.
My recommendation is to run a nightly, weekly, and monthly backup. You then have multiple spots that you can look to to recover files. When I worked as a CAD Manager in the industry, we saved each daily backup for 7 days, each weekly backup for a month, and the monthly backups were saved permanently. In this way, we always had a spot to go back to and recover a file if needed. Sometimes you may end up with a file a few weeks old and recent work is lost, but it is still better than losing the file altogether.
You can also use the AutoCAD backup files to try and get damaged files back. A BAK file is created with each Save that is done. This BAK is saved in the same folder as the DWG. In order to use that file, you would rename the BAK extension to DWG and then it can be opened normally. Additionally, the Autosave will create a SV$ that can be renamed and used in the event of a crash. The link below does a great job of explaining how Autosave and Backup files work:
With a great backup system in place, your chances of losing a file altogether become very slim. A Google search for backup systems yields numerous results and you can then choose the one that best fits your needs. Let me know of any questions.