Over analyzing can cause stress just as much as external factors that you face.
Rumination, procrastination and overanalyzing can be harmful to your health. Think about it, do you go over in your head situations that could have happened? Or, do you find yourself stuck when it comes to making a decision or taking action? This is a problem because it can keep you from taking decisive action, and cause stress too. You can fix this by getting your priorities in order and reminding yourself of those priorities so that you can take action helpfully.