If you're unable to leave a family organizer account because you don't know the organizer's email, you may need to try reaching out to Microsoft Support for assistance. They can help you verify your identity and potentially provide you with options to regain access or remove the family organizer association. Unfortunately, without the email, it can be difficult to manage family settings directly.
Additionally, ensure that you have the correct information about your account and any associated accounts that might help in the verification process when contacting support.
References: