Do we need to calm down?

During my recent, much needed soul searching, I've found out the one thing that I believe we all can live without - stress. My research has told me that stress has much more impact than I originally thought.
Did you know that stress can actually make you ill? Of course you did, I'm sure. But you didn't think that it was enough of a threat to change your behavior, did you?
"Some day the medical profession will wake up and realize that unresolved emotional issues are the main cause of 85% of all illnesses. ." - Eric Robins.
This seems to make perfect sense, and I think that if we all just calmed down a bit, we'd be so much healthier. I listen to friends and family talk about what gets them stressed - and although I sometimes think 'do you really need to be getting so worked up about this?', I do exactly the same thing.
When we're stressed, our body actually releases toxins - but we're all so programmed to anxiety, so how do we go about changing that? Is it really that easy to just cam down when none of the external causes to our stress have changed?
One's quality of life isn't determined the events that take place; but the way in which these events are interpreted. So surely all we need to do is react differently to life's problems?
Since I've discovered the potential impact prolonged stress can have on our health, I've made an effort to try to approach life a bit more calmly. However, now, when I get stressed, it seems that I get more stressed because I know I shouldn't be stressing, and then I realise I'm stressing about being stressed from being stressed and it's just one big circle.
It's obvious that everyone encounters stress - it can't all be bad can it? Fear and excitement are the two most similar emotions we have - according to our body, there's very little physical difference between the two. Excitement released endorphins...so does that mean that fear must be healthy for us? And, surely, stress can't be that different from being scared, can it?
I think that the fact I'm getting so worked up about trying to calm down is a paradox worth ignoring for the time being, before my head explodes.