Facebook Can't Log in

Registration date
Thursday December 3, 2015
Last seen
December 3, 2015
All of a sudden, just tonight, I can't log into facebook. It keeps coming up with google...I tried updating facebook..that didn't work. Then kept saying I need to download it from the app store....I already have it on my I pad..and anyway..it won't let me download from the app store. I think Google is preventing me from using it. I got a message from Google saying someone had used my account, and had to change my password, which I did. Now I cant do anything... please help!!!,