You do have a way to come up with very complicated issues.:-)
Since you did not have security questions, you should not have tried to guess because this complicates the recovery.
Remember, when trying to recover any account, Facebook or otherwise, you are not dealing with a person but a robot who is mostly programmed to filter, send automated answers, when in doubt it blocks.
It is my belief that your account was hacked and I have provided the recovery methods in my first message, they are the only ones that exist.
Should they fail for you, I have none other to suggest.
Sorry but that's the way the cookie crumbles.