What to do when I can no longer access to email that I registered as my ID?

See If you forgot your Apple ID password https://support.apple.com/en-us/HT201487

You also can use Having trouble signing in/iForgot  https://iforgot.apple.com/password/verify/appleid 

You might as well also See If you forgot the answers to your Apple ID security questions https://support.apple.com/en-us/HT201485

Go here if you need additional support Apple telephone support https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

For worldwide Apple ID support go here https://support.apple.com/en-us/HT204169

If necessary, contact Apple ID Support. See the Apple Support articles below for contact information.  

Apple ID - Official Apple Support.    

Contact Apple for help with Apple ID account security - Apple Support.   (Link doesn’t always load)  

Get Support          Work through the screens to get a chat option. 

https://twitter.com/AppleSupport

From the Apple Support article below. 

Without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account. These policies are audited and reviewed on a regular basis.

Security and your Apple ID - Apple Support.