You cannot change your login method from SSO/Google to email and password on your own. If you want to switch from Google Auth to username/password, you'll need to talk to a human.
To request human assistance, click on "Talk to a person" in this chat.
Just changed your login method to password! Try going to the sign in page and look for the password reset button. Click it and send the reset link to your email and you'll be able to set the password to your account. Let me know how this goes.
