Restore an earlier version of my database

No need to create a new, separate thread when the problem is already addressed here.

The only way to restore to a earlier version of your database would be from a backup. If you do not have one, contact your host ASAP as they may do regular backups and may be able to provide you with a snapshot of your content as well as restore your site.

Once back up, there are plugins that can help you do regular backups of your database and files:

Free: https://www.ads-software.com/plugins/backwpup/
Paid: https://ithemes.com/purchase/backupbuddy/