Yea that is a tough one. Perhaps you need to recover the password? Maybe some apps are registered with a different gmail account? The description is limited, but the only time that I have experienced this is when I was logged into the GOOGLE suite with my wrong ID. Try to get into your google account, and see what services are attached to it. Any apps that aren't listed, aren't attached to that account! SIMPLE!
I did try to Get in and I told them the correct month and year I made it and also the number and name on the account and used all my back up codes and still can't get in but it's open on my iPhone mailbox it sends me the verification codes and that don't work