Stress is used as a noun as well as a verb. As a noun it has divergent meaning. Examples:
(i)I am full of stress because of pressure of work. (mental or physical strain caused by pressure)
(ii) In our family, the stress is on a good education. ( give emphasis or strength)
Both stressed and stressful are adjectives meaning worried and full of tension.
Examples: He leads a very stressful life.
I'm stressed because of my son's drinking habbits