Can tu please help me? I need it!

I'm actually Renegade1765, but I accidentally made this alternate account, so whenever I log in, I log in as Gameboy instead of the Renegade. I tried everything, but I always log in with this alternate account, when I want to use my real one. I even tried to get rid of this new account, but I need to input my password, but because I'm connected with Facebook, I don't have a contraseña thus I can't erase it. Please, help me.