Failed to start session after adding a variable?

I have been trying to set up a different terminal as the default terminal used with mod+enter combination, downloaded Terminator. Because the shortcut was not working, I have been trying various solution for example adding TERMINAL=/usr/bin/terminator to the .profile file. I have also edited .Xresources. I have restarted the system and cannot even log in. After providing the credentials I have a “Failed to start session” message.
Is there anything I can do other than starting installation from scratch?