Primafacie,
So sorry for what you went through with your dad, I understand what it's like to find out that a parent drinking problem is much worse than it seems, I am sure your parents were only trying to protect you, hoping you would better understand as you got older.
I am sorry that one or both of them continues to be deceitful about the drinking isuues.
I believe lilotto is being unfair when he describes your behavior as meddling, I don't see how that advances the conversation or offers you any support. Please be assured most people here would not be so inconsiderate.
Please take care of yourself and let us know how things are going.