Hi and welcome to the site, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially and other than the phone, do you have a secondary / recovery email address?
A Gmail account can be potentially recovered if there is a recovery contact information that Gmail can use to reach you; a phone number and/or a recovery email address.
If none, then there is no way for Gmail confirmation to reach you.
When was the last time you were able to open your Gmail account please?