Accidentally got locked out from Azure after I changed my account from external to internal (Azure for Students account)

Similar issue as https://learn.microsoft.com/en-us/answers/questions/5494274/locked-out-after-converting-only-azure-ad-guest-us

I have an Microsoft Azure account linked to Azure for Students - and I got accidentally locked out after changing my external account to an internal account. That account has a Azure Databricks instance running - and due to me cannot access the dashboard initially, I decided to change some options on the Azure settings where I feel suspicious - which then I accidentally get locked out after changing it from internal to external. The solution listed on the issue is to log in with the internal parameters - but I partially remember some parameters from the UPN but I forgot the ___domain I used for the UPN.

I created a new directory as well using the "free trial" offer ($200 credits for 12 months) but after adding a debit card it said I'm not eligible, and a new directory without any subscriptions is created as well. Any solutions? I can provide the tenant UUID as well. The debit card does not appear on the Microsoft account as well.

Is there any way to regain access to this directory, provided that I know most of the history associated with this directory? Thanks.

Here are some screenshots to help with the troubleshooting (UUID cleaned from image):

UPDATE: I figured out the username/password for my Internal User account. Note that the syntax is [NAME]@********gmail.onmicrosoft.com (if your email is ******@gmail.com, where NAME is the internal user name). Password and verification methods are the same as your original account. Solved by myself.