So, lets say it is truly "stress". What is the cause? Have you discussed this with him? When I am feeling stressed out, my Dom senses that something is wrong right away and makes me sit down and talk it over with him.

Then, if I want or need suggestions on how to deal with them, he offers his thoughts or ideas (when he can). Other times, it is just helpful to be able to vent. After talking with him, I am usually able to get my mind off of the cause and focus my attention on other things.