Thank you for a full and relevant history.
I presume that after all those investigations, you have seen a Consultant at the hospital.
Polycystic kidneys cannot be ignored as a diagnosis, but as you haven't mentioned any problems with your "water works" e.g blood in the urine or UTI.s then it makes it less likely as a cause.
Infact those symptoms could be due to a multitude of diagnoses and "guessing" would be just that...guessing.
Go back to your GP or Consultant, perhaps an MRI scan but do not let those symptoms rest without further consideration.