My account has been hacked with a total email address change and recovery emails not working

My Microsoft account was recently hacked--I'm not sure when, but I suddenly found myself unable to use the Authenticator app to log into my normal account and suddenly found that the email address attached to that authenticator is completely different. However, I do have the listed email address of the compromised account in question and would like to contact someone to notify them and try to recover my account, as Microsoft's listed normal methods have not worked for me.

(I am currently operating on a new email address)