My Facebook Account Was Stolen - Lost Access After Email & 2FA Change

My long-standing Facebook account has been stolen. The thief not only changed the email address but also activated two-factor authentication. When I enter my registered phone number, it asks for one of my old passwords. I enter an old password, but since I don't know the two-factor authentication code, I'm directed to the 'Do you need another way to confirm it's you?' page. Clicking on the 'Go to upload ID' button prompts me to enter my email address. Even after entering the code sent to my email, it's not accepted. I've tried everything, but nothing works. What can I do? Is there anyone who can help?