Not sure how this happened but a few days ago I logged into my account, through facebook as usual, and my account name had changed to "Salatow" and my country was listed as Russia instead of Canada. On top of that in my game history in multiplayer there were games listed that I didn't play and stats that weren't mine. My 20 games in multiplayer ranked were being used without me using them. Even the costume on my avatar was changed, with items I never bought. I didn't change anything myself - it's as if another person and I are using the same account at the same time. I tried logging out and back in again a couple times but otherwise I've been logged in this whole time. It doesn't seem like this other person is doing anything nefarious, from what I can see they've just been playing normal games of geoguessr and probably don't know what's happened either.
Has this happened to anyone before? And how would I go about getting control of my account again?