Hi,
I'm sorry you are experiencing this issue. The recovery form may no longer be detecting your account because it may have already been changed and deleted by the hacker.
I really wanted to bring you good news, but honestly, if the hacker changes your email address and other information, recovering your account can be challenging, and it may be permanently lost. I understand that this is a difficult situation. You can check the Microsoft article below to see if it can help.
If none of the steps work, I’m sorry to say that since the username has already been changed to a different one, it means the account has been taken over by the hacker. There is no way to recover it, and it is now unfortunately lost.