I don't want to tell my parents the truth why I drank myself unconcious.
You drank yourself unconscious? How do you think they'll feel about this?
I fear I'll be grounded if they find out about my drinking incident.
I understand why you would have a hard time telling your parents about this. But parents are there to help and being truthful is important.
My parents won't care.
I'm sure your parents will care about something like this. You should tell them the truth about what happened.