unable to access my email account

Can't access my email account, doesn't recogonize my email and password, that I KNOW is correct!  Have tried to reset, it takes me to the at&t site, which is not helpful, they do not show my bellsouth.net account only my uverse account.....very frustruating!!!!!!!!!!!  I have called yahoo help, and because of the high volume, they are no longer accepting phone calls!  HELP!!!!!!!!!!!!