I think Mira is asking how to apologize for the misunderstanding and confusion we caused, not for we misunderstood or confused what others said. I'm sorry I made you confused=不好意思，让你误会了(made you confused) =不好意思，我没说清楚(I wasn't clear) I'm sorry I misunderstood you=不好意思，我误解你了

不好意思，我搞错了

抱歉，我误解了

To be honest, in speaking expression, Chinese people are not often to say out the words "misunderstanding" of "confusion" . Instead, we often say"对不起！我弄错了！"or “不好意思！我糊涂了！”

the people who come from southy China speak that like Pai se la ！ and thats cooler.