Hey there! Nice to meet you!
I'm sorry you are experiencing this.
Based on your description, the hacker was able to remove the account's security info and replace it with their own email address.
Since the security info has been replaced by the hacker, I'm afraid there is no other working method to recover the Microsoft account, and Microsoft Support cannot help either.
However, please follow the guide from this thread to remove the hacker's account from your device: https://learn.microsoft.com/en-us/answers/questions/3916526/my-microsoft-account-was-hacked-and-i-am-unable-to?forum=windows-all&referrer=answers
Thank you for your understanding.
Best regards,
Darhyl