Tried to log in to facebook but couldnt remember the password....?

[Laura]

so i went on to change password and it took me to my email....i couldnt remember that password so i sent the code through my back up email address on that account and changed the password to access it....i then changed the password on my facebook through my normal email address but it came up with someone elses name called anna root :/ i changed the facebook password and logged in it took me onto someone elses facebook page despite being my email address how does facebook do this?? can i get my own account back?? or has someone hacked it and changed everything??