Using older versions of Outlook for Mac for personal email and calendar
I’m so sorry about this, ProjectRejected.
It's reasonable to try years to recover an account, especially when it contains important information and was also how you stayed connected with friends and family. Unfortunately, given what you described, the situation is not looking ideal. I know it's heart-breaking, but I want to be realistic with you rather than give you false hope.
In a normal process (with Sign-in Helper), you would need to verify that you are the account owner before proceeding. This is nearly impossible if you no longer have access to the verification method, do not remember the password or previous account information, and the recovery form has already been rejected.
Generally, Microsoft recommends submitting the recovery form again only if you can provide additional information that you did not have in your previous attempts. If you have been essentially submitting the same information over and over again, unfortunately I would not expect a different result.
You can still contact Microsoft Support if you want help reviewing which recovery options remain available, but keep your expectation low. Microsoft forbids its agents from bypassing that verification or manually grant access simply because users have "reasonable" circumstances.
I know that is probably not the answer you were hoping for after keeping it up for so long, but I thinks it's better to be honest with you. I hope you can get through this difficult time.