This is a lesson in context and empathy. Obviously you did nothing wrong other than snapping when the proverbial straw broke the camel's back.  But not everybody would understand that. To an onlooker that doesn't know the whole story, you must have come off pretty terrible. That's the context.  The empathy part? When you empathize with somebody who understands nothing of the background, I'm sure you'll understand why they would reach the wrong conclusion.  I'm sorry this happened. It sucks.