Guys I have dont a mistake in the administrator setting. I go to admin and change some under SETTING > AUTHENTICATION

Yesterday I change something and click ok mistakenly and log off from Admin. Today I cannot login telling that my password is wrong. I requested forgot password, reset and email me one but that too cannot. All visitors on my sit cannot login though we r using the correct passowrd it say wrong password.

How will I get back same password or even if password need to be change, I dont want to lost usename or data anymore. Please help