So, I know I wasn't in private browsing, and I didn't clear my history, but there is NO RECORD of my previous session AT ALL! I've tried the links provided, but I just get an error. What happened? Okay, it's in my history, but the Restore Session button is grayed out and when I right click, all I get are shortcuts to my new session. It's seriously like it disappeared. And if this is the wrong place, try to move it, I guess...

Nevermind. I uninstalled and reinstalled Firefox, and my session was recovered. Wow, I was really scared there. This topic will be closed now.