The act of re-evaluating one's thoughts in response to a stressful situation is called "Cognitive Reappraisal". This takes the form of identifying how accurate or rational one's response was, or in some cases determining the true importance of a stressor or if it is even worth reacting to.
One use of cognitive reappraisal is within the process of (insert hyperlink) Rational Emotive Therapy (REBT). REBT involves taking a step back (metaphorically) and viewing an "Activating Event" in a more emotionally detached manner. The mental and behavioral responses are linked to it as a type of chain, followed by the ultimate outcome. In closely examining one's mental responses (which typically happen reflexively), the resulting emotion, behavior, and the outcome of that behavior as compared to the goal (emotional or situational goal) can be assessed. When the outcome is not the desired outcome, identifying alternate ways of thinking and behaving are identified, and productive changes can be made.