Hello @Brandon,
Based on your issue description, it appears that you accidentally deleted the Entra admin Microsoft account for your Authenticator app due to an incomplete MFA process. Since the device registered for second-factor authentication are not getting any MFA prompts, you are unable to complete the authentication.
In such scenarios, another Global Administrator can help to re-register MFA on your mobile device. However, since you mentioned that you are the only Global Admin in the tenant, this qualifies as a tenant lockout scenario. To resolve this, we need to engage the Data Protection team via a support ticket to unblock your access.
To proceed further, I will need a few details from you. As this information contains Personally Identifiable Information (PII), please share the following details via private message:
Contact phone number (add +Country code)
Contact email address
Global admin email address (affected admin account)
Country
TimeZone
Please send me the above requested details via private message and I will proceed with creation of support ticket with Data Protection team and they will further assist you in resolving this issue.