Hello, thank you for reaching out to Microsoft Q&A.
May I please know if you can sign in with your Microsoft account (the hacked one) here?
https://account.microsoft.com/
Open an incognito tab and paste the link above. See if you can sign in.
If you receive the error message “This account doesn’t exist,” it is possible that the hacker has completely removed or deleted your email address (alias) from the account and replaced it with another one.
If this happens, it will not be possible to recover your account. According to Microsoft policy, if you remove a Microsoft domain email address, you are permanently deleting that address, and it cannot be associated with any other account again.
So, let me know if you are able to sign in successfully or not.