I just did a system restore (rolled back like three days). Nothing changed.

A system restore does nothing for Firefox. As the Name says System Restore. You can try : https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

If that does not work their is a NIRSOFT Program that may work. NOTE : Your AV Program will not like it. It is safe though. http://www.nirsoft.net/utils/passwordfox.html

Remember delete is often delete (gone for ever).

Please let us know if this solved your issue or if need further assistance.

In the event that the passwords information is lost, you should record all information in a separate text file somewhere else on your hard drive, or written down. You can easily copy and paste if you need to do so. If you are concerned about someone else looking at that file, you can compress it using a password.

These can't get your data back, but will help in the future.

These add-ons can be a great help by backing up and restoring Firefox

https://addons.mozilla.org/en-US/firefox/addon/febe/ FEBE (Firefox Environment Backup Extension)

FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.

https://addons.mozilla.org/en-US/firefox/addon/opie/ OPIE

Import/Export extension preferences

Well, lost is lost. Gone is gone.

Copying and pasting all my usernames and passwords for years worth of accounts doesn't sound fun, but I guess I'm experiencing the worse option right now.

Thanks for the suggestions for the FEBE Fred. I will try that from now on.