A book I read suggested the following formula for stress:
So if you're stressed out of your mind, that gives you two variables to adjust.
There's a pattern in the news flashes I see when reading financial information online. It typically has a headline saying something like "Expectations dashed as market takes big hit" and shows an image of some broker, in anguish, burying his face in his hands. It's hard for me to feel bad for that guy. He's the one who based his ability to perform on factors behind his control.
If you're finding yourself in a situation like that, then get in control or get out. There are other opportunities out there and It's not worth the stress.