Problem with my password.

Can you please help me with my password, I got a message from yahoo advising me to change my password that it was not strong enough I did,and I was require to get an alternative email for my account which I have being using since 1997,i created a Gmail account unfortunately I can't remember the user name not to even talk of the password of the account, I dumped the number attached to the email years ago,right now I need help on how to open or retrieve my password, or my secret question.