I understand your pain about disappointing your parents but if you really don't want to fly - DON'T.
Perhaps a little white lie to your parents? - A medical exam has highlighted an obscure defect with your vision, which means you can't get a Class 1 Medical (or whatever is required where you intended to fly).
Create a career in some other field, earn money - pay back your parents what they've layed out so far. One day, further down the road when you've no doubt made a good success of your life in this other career - you can tell them about the eye story. By then, they won't care; they'll be too proud of what you have become.
Good Luck!