I blame my father for my brother's behavior
Do you really think your father is to blame?
I think I should blame him for that, but I know it has nothing to do with him.
Your brother is his own person. It's not anyone's fault but his own for his behavior. That's how people grow and learn from their mistakes.
I'm still mad at my dad.
You are placing that anger on the wrong person. Are you sure you are not jealous? Because your dad had invested time on your brother?