There's a lot of things to say, one's tolerance to stress, self image, etc.
One solution is realizing that there are few things in your life which you cannot control(a car may flip right in front of your face, for ex). The rest of the things, there's your responsability.
Almost everything is reaction from your action. Realize
that you have more power in almost every situation you encounter in your life than you imagine. And it's your job to deal with these stressful moments. Take a deep breath, ground yourself, feel the power, the responsability of your actions and the situation you're facing, then act.
Realizing is in the first place, accepting the situation, accepting the stress and then you do something about it, in a healthy way.
I have a saying: A real man do whatever he wants and he assumes all the consequences. That man has the power in his life. But he must realize that he has it, and must take responsability even for the things he didn't planned to, but he's facing now, because that's what a man do.
You'll get better with time and you'll know what to do. Good decisions come from experience. Experience comes from bad decisions.
Maybe this video will help you: