Hacker changed microsoft account mail

My Microsoft Account got hijacked. To recover it I need to put in the Mail of the account I lost access to, unfortunately the hacker changed the Mail so I obviously don´t know it causing the ACSR Form not working... When I searched for what to do if ACSR fails I got 3 things suggested to do and if I understood them right all of them required me to put in the mail of the account agian and I still don´t know it, what should I do now? Did I do something wrong?