I lost my phone, I haven’t given any alternate email, and fogotten the answer to security question. Now, how can I access my Yahoo my account?
Check it out here for recover your account (Yahoo Helpcentral)
You've certainly done a good job of making this difficult ; - ) Nevertheless, try contacting Yahoo's Customer Care at https://io.help.yahoo.com/contact/index?page=contact&locale=en_GB&y=PROD_MAIL_ML and see if they can help you.
What if I forgot my password and/or Yahoo! ID?
You can get a new password, a Yahoo ID reminder, or both. Visit the Sign-in Problems page and supply some basic verification information, such as your birthday and the ZIP or postal code you provided when you registered.