an old mail of mine (7-8 years old) was (most likely) hacked and I can't get it back because all the mails I send and got are years old. or I dont know the information anymore. but I really want my account back.

the mail for receiving a code has been changed to a mail which is not mine. and I can't see the complete mail.
I have talked to some people already but they all ask stuff I don't know anymore or dont have.

Is there anyone who can help me?

-Linda