Facebook password pop-up

I found another thread for this but none of the suggestions worked, so I am reviving it. I'm getting a pop-up titled "Facebook Password" that asks me to "Enter the password for (my email) in System Preferences. If I hit cancel, it just pops back up. If I go into System Preferences and enter my Facebook credentials, it tells me "Unable to verify account name or password." Interestingly, if I enter the wrong password, it does nothing. But if I enter the right password, it gives me that message. I've tried to 30 times - I'm not typing it in wrong. I'm getting ready to trade in my Mac. So tired of all the bizarre pop-ups and weird chain passwords and crap that comes with using an Apple product. It's always something!