Can't access Yahoo Account! HACKED?

Hello,
Yesterday my email was working fine. I never changed my password, however now I can't access either of my yahoo email accounts anymore. I assume they have been hacked and someone changed the passwords. Problem is, the phone number I entered was an old one and I don't have access to it anymore and stupidly as my back up email (for the more important account) I entered the other yahoo email, which obv. I can't access. I really don't know what to do. Is there anyway for yahoo to reset my password to the one from yesterday? Or for me to access the account?
I hear others have similar problems - any way to fix this?
Help would be appreciated!