The sales industry can be a very good business to be in until a few of your deal go south or start to show trouble. Thats when the stress starts to build up and your neck and shoulders start to tense up and you feel like your office has a built in heater.
I have been in the sales industry for many years and there is a natural stress relief and it is really good for you. Sometimes it can be very hard to do because you are fighting it, but try it and I am positive it will work.
When you get the symptoms, simply get up from you desk and take a walk. Yes thats it, take a long walk, get as much fresh air as you can take(breath deep). Listen to the birds , look at all the sites and maybe even talk while you are walking. lol You got to get it all out and then you can go about your day.
You might think I am crazy but try it for yourself and I bet you don't do it just once.
Now after your walk you will feel like a new person and I am sure the problems will get worked out because you will have a new attitude. I am not saying to put it off. I am saying take a walk, come back with a new attitude and attack the problem.
I am sure if you do this it will work. Years ago I had a Sales manager who would drag me out of the office and make me go for a walk with him. Took me a few years but I figured out what he was doing and it works.