By delete your azure account you mean delete your subscription as well.
If you dot have access to the portal again because you lost you MFA, I will recommend you reach out to another admin to help reset your account.
If you are the sole admin, you will need to reach out to product support to reset your MFA credentials. See:
https://azure.microsoft.com/en-us/support/create-ticket
Or the global support numbers:
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola