I tried that 'index.dat' method but I have a million index.dat files and none of them are related to Firefox. Also it sounds fishy af.

It is possible that there has been a problem with places.sqlite (bookmarks and history) and that a new database has been created. In such a case the bookmarks are rebuilt from a JSON backup in the bookmarkbackups folder, but there is no backup of the history.

You can check if you have a places.sqlite.corrupt in the profile folder and possibly try to rename this file to replace the new places.sqlite. Make sure to keep a backup copy of the current places.sqlite.

If you can't use this then only an older backup of places.sqlite might restore the lost history.

You can look at a utility to browse System Restore points.

• https://www.shadowexplorer.com/
• https://www.nirsoft.net/utils/shadow_copy_view.html

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

I actually looked into places.sqlite with the notepad and, even though its mostly gibberish (obviously) I did find that websites are actually stored in plaintext, and it would appear as if my history was there intact.

I searched for some of those adresses my history/bookmarks inside Firefox and they don't show up, but I do remember having visited many of those. So the information is still there, only for some reason Firefox isn't reading it.

I don't have a .corrupt but I do have places.sqlite-shm and *.sqlite-wal.

Oh and I don't have system restore active ):