Hi _256MAD
Welcome to Microsoft Community.
Based on your description, I understand that you are unable to log into the system after changing your email address, and I understand how you feel!
It may not be accessible through Advanced Mode at this time either, and I will give you a thread with a relevant solution, one that I have tested and works after receiving your question.
The thread link is: Locked out of PC by Windows 10 - The fix is here! - Microsoft Community
In step 4 of that thread, please start by following the actions in the thread.
I will give you some other commands that can be executed as backup commands.
Create a local account with administrator privileges and log into the system through that local account:
net user USERNAME PASSWORD /add
net localgroup administrators USERNAME /add
Please note: USERNAME PASSWORD can be replaced with your preferred account name and password, if you don't need a password you can leave out PASSWORD.
Enable the hidden administrator account:
net user administrator /active:yes
If you are unable to sign in to your Microsoft account, please contact Contact Us - Microsoft Support for help and support related to the issue, thank you very much!
(1) Click the link to visit the website and log in your account
(2) Enter the problem you are experiencing in the search field
(3) Click on "Get Help".
(4) You can check whether to write help or seek online support.
I sincerely hope that the above solution will solve your problem. Please feel free to contact me if you have any problems or still can't solve them.
I look forward to hearing back from you.
Best Regards
Arthur Sheng | Microsoft Community Support Specialist