This is the only possible way you can recover your account. If you don't succeed, you must open a new one.
You can get a new password, a Yahoo! ID reminder, or both. If you forgot your Yahoo! ID or password, go to the Sign-in Problems page. https://edit.yahoo.com/forgotroot/
Just type your yahoo ID and click submit. Then, click on security question type and click Next .....
You will get a recover link ..