Eu nao gosto muito de traduzir frases por geralmente as pessoas querem uma traducao ao pe da letra. Mas como um velho amigo me disse, "uma lingua nao e a versao traduzida da outra." Mais vou tentar te ajudar:

I made a mistake and went through the wrong gate.

Or, I got it wrong and went through the wrong gate.

He misunderstood you with your sophisticated language/lingo/speech...

Or, You got him confused with they way you were saying...

I thought it was the rain but actually it was his tears. (Eu nao consigo usar confundir aqui nem em Portugues)

He had me confused with my sister.

Or, he got me confused...

I made this huge confusion with everybody's name.

He made this huge mess after getting drunk in a bar.

I hope it helps,

Sid.