Sorry for the late reply. But my opinion is to just tell them what you feel, if you don't want to get nuked with words when and if you fail. Communication is important. If they do love you which i'm sure they do, they will understand. Maybe not immediately but with time they will see where you're comming from. Maybe that day, in a month, or 20 years. Just prove them they're wrong. Even the greatest geniouses can fail at school.