I destroyed the family's car by driving it into Lake Michigan
I think you should tell someone you drove the car into the lake. What did you tell them?
I'm not telling them. I told you that I was crazy.
You damaged your family's car and not it is not driveable, it is not okay to not tell them and brag about it. This is a huge financial loss if not reported to insurance, you need to tell them.
I'm not telling them.
You need to tell your family. You destroyed their car so now you need to take responsibility.