The fill level tube could be clogged and not giving you a proper reading.
As far as what to do, I don't think we have enough information to make a clear decision. However, my advice would be not to wait too long. Get it checked quickly, maybe drain out some water. Does the system have a pressure guage? I would reduce the pressure immediately and look to see how the leak responds. Then call a professional and see what they recommend over the phone. Good luck...