The Buddhists say suffering is caused by desire. The psychologists say stress is the perceived lack of control. You make a choice to desire something you lack control over achieving or not.
Lets say you want to lift a heavy box. You can keep struggling with it or you can get a dolly, ask someone to lift it for you or forget about lifting the box completely. In life I see people with their mind set on unattainable goals, stressing out for nothing. They might want to feel "cool" so they buy fancy clothes and cars. Then they don't have the money for rent so they work longer but then get tired and fat. Then they go on a diet and buy fancier foods but it doesn't work. So (proverbially) as they tune one string, the other gets pulled out of tune and they just get more and more stressed, never thinking to just put down the guitar. Don't kill yourself. That's not the analogy but stop all the BS that you're stressing about.
Like Gorge Carlin says "it's not that difficult. Get up, eat breakfast, go to work, take one good dump and go back to bed." Maybe there's some fun thrown in there but I don't understand how everything has to be so stressful for some people.