Unable to access sbcglobal.net email account

Hi,

I've been using my sbcglobal.net email address for about 20 years and I have a massive amount of important/personal information associated with it. A couple of months ago, my daughter tried signing into my account on a new device too many times and locked me out of the account. I never added a backup/recovery email or anything to this account (yes, I know now this was a terrible mistake).

Every time I go to reset my password for the email, I get the message "Hmm, we can't reset your password. We don't have the account details we need to reset your password right now. To get help, call 800.288.2020". I've called that number before and they were unable to help me.

I originally didn't think much of losing access to my email account because I was still logged in on my phone and iPad. As of this evening, I officially lost access and my email won't update anymore on either device. I'm very freaked out and don't know what else to do at this point. I'll do as much as I can to prove this email is mine and to regain access.