Lost My Temper with a Customer

Today at work was one of those days where everything goes wrong. I was feeling particularly down and worn out from dealing with difficult customers all day. Just as I needed a break, this demanding customer came in, asking for an impossible request. Normally, I wouldn't let it get to me, but today I snapped. I raised my voice, something I never do at work, telling him he could find his coffee elsewhere if he couldn’t be polite. After that, I felt awful and guilty. Not only did I break a rule about customer service, but also the respect dynamic with my partner who expects me to maintain professionalism even under stress.