how did you back up the account and where did you back it up to?
is this backup what you can not access or is it the main google account that you can not access ?
i would just create the archive again and try putting it on google drive and copy it from there. But tbh it doesnt sound like much of a backup. In my opinion backup methods should be straight forward super easy and never fail. This is what you are counting on when everything else is gone. if it has problems once, its not dependable enough to be trusted as a backup.
i think i am going to have to opt out for now i am not sure what type of backup it was and if it was even designed to work after you deleted the original account.
somebody else may have used that and can help you easier. If nobody picks up for you i will come back and do some research on it for you.
I have done some research and I have some really bad news
What happened when you asked if to email you rather than put it on one drive is that you never got the actual data. Instead the archive was left on the Google servers and you were emailed a link that you could use to download it to your computer
That would have worked EXCEPT that Google only stores it there for a week. Whether you download it or not Google deletes the copy on their servers after 7 days
You can try to recover deleted emails in the original account. If they are no longer in the trash folder you can fill out the form on this page