I tell this to everyone I know who "suffers" from stress, and I get some variation on the same response, "it's not that easy for me".
Actually, it is easy. It's 2011. Predators aren't chasing you across the savannah. You're not more than 3 days away from a source of potable water. You're not more than 7 days away from safe, nutritious, calorie dense food. You aren't in immediate danger of being washed away in a flood or dying of heatstroke in the desert or freezing to death.
Realize that your "stress" is so far removed from its genetic origins as to be laughable, realize how good you really have it, and enjoy life.