Unfortunately, the account is gone. Even if you deleted the OG number, IG still remembers it.
If you still have acess to email, request a password. Change the password and after it click “secure the account” and magic is works!
It will still prompt you for your number…
This is correct, as side effect: the OG number can always be used to restore an account - no matter what you did, who sold it to you or who you sell it to