Stuck in Limbo between Yahoo and AT&T

Yahoo will not accept my password. When I use "forgot password" it sends me to AT&T. AT&T will not accept my password because I no longer have AT&T (I have COX). The email I am trying to log into ends ***@***, so I should be able to separate Yahoo from AT&T but it won't let me. I am sent round in circles. Have tried calling both Yahoo (no call back) and AT&T (no help -- it's Yahoo's problem). What can I do? This is impacting my business. HELP!