Either Microsoft is once again displaying their incompetence or you've been hacked somehow. I suggest that you navigate to the "help" section and visit their support center. You might find the solution to your problem there.
Have you checked the inbox/spam folder of your account's email address? If there's nothing suspicious to find, it's probably Mojang's fault.
I checked the email that my account was registered on but since mojang doesn't recognize the email I don't receive and emails