Hello,
It appears that the hackers removed your email address (alias) from your Microsoft account and replaced it with their own. When an alias is removed in this way, the email address may be permanently deleted. If it belongs to a Microsoft personal email domain, it cannot be linked to another Microsoft account or recreated.
To help prevent this from happening, Microsoft always recommends protecting your account with a strong, unique password and enabling two-factor authentication. This adds an extra layer of security because, even if someone knows your password, they would still need a second verification method, such as a security code or the Microsoft Authenticator app, to sign in.
In this case, since the account has been deleted, you cannot use the standard account recovery form.
Instead, contact the Xbox Account Recovery team, which handles compromised accounts even when the email address has been changed. Be sure to provide all required details accurately when you submit the form.