So, you cant use an alternate email, unless you set that up WHILE you are logged into that specific account.
YOu cant add in an alternate Email or phone number unless you can login to that account.
In addition, if you have designated a specific phone number to be your RECOVERY option, and now you dont have access to that phone number anymore......you have effectively locked yourself OUT.
Yup, it does happen.....and there is little to NOTHING google will do for you.
These are FREE email accounts......and Google does NOT provide LIVE support for them. They will only provide automated support (FAQ's, and user forums)
So, i can offer to remote into your computer, and see if I can find a way in.....but honestly it doesnt look good.
Let me know when you are ready to do this,,,,,as it might take 15 to 30 minutes.