Google account can't login because I forgot the password hint question. Even with the password remembered. What can I do?

I have an account named some1234.com@gmail.com (some1234.com is a domain owned by me, but this is a placeholder)

Current situation of mine:

1. I have the password. I am sure of this.
2. I own the domain some1234.com
3. I still can receive email because I have set up a filter to auto-forward the email of some1234.com@gmail.com to my primary email address.

But I can't login. Because Google needs me to answer the question to recover the password. Even if I have the password.

This is so annoying. I really need to get the Gmail back. What can I do? Is there a human support available?