I too catch myself and apologize for being so frustrated and angry and say ” I don’t mean to yell at you I am just so upset, I know it is not your fault but…… can you help me out?”
As far as the rude client is concerned the only way to deal with him is to tell him “excuse me, please understand that yelling at me and abusing me is still not going to make this happen any sooner. If I could miraculously have it ready for you sooner believe me being rude to me would not be the best way to make that happen. And if you continue to yell at me you will leave me with only two options one to put you on hold for a few minutes to allow you to calm down and regain your civility or two to consider this conversation over and hang up.”
That would be like throwing a bucket of cold water in his face.
Many years ago I worked for an accounting office in Boro Park. This one client called in and started to throw his weight around. He wanted to talk to the boss and I politely asked who he was. He blew up and started yelling at me, you don’t know who I am? I am so and so and how do you not know who I am, I am your most important client, on and on and on. When he finally calmed down I said “Well Mr. “X”, you might be the most important client and you might be a client here for 10 years, but I just started here last week and I have yet to learn all the clients so do you really expect me to know who everyone is already?” That humbled him in zero to 60. He was so apologetic, after that each time he called he introduced himself and asked how I was doing.