I made the mistake of letting the browser automatically update. Today when I turned on my computer Firefox opened a fresh page (deleting all the tabs I had open) asking me if I wanted to import saved passwords and browsing data. That was annoying enough on its own, but instead of importing from the old version, it imported everything from my other browser which I had kept separate and different for numerous reasons.

On top of that, when I try to load web pages of any sort, it just sits there loading and does nothing so the browser is entirely unusable to me right now. Please tell me that there is an easy fix and/or a way to get all my data back.