Final answer:
Steph most likely has an anxiety disorder, which is indicated by her chronic stress response to psychological stressors, including increased heart rate and excessive worry without using adaptive coping strategies.
Step-by-step explanation:
Based on the symptoms described, such as increased heart rate, sweating, and imagining negative scenarios without using adaptive strategies, Steph is most likely experiencing a psychophysiological disorder. These symptoms are often associated with the body's fight or flight response, a reaction intended to prepare us for threatening situations. However, when this response is triggered by psychological stressors in the absence of physical threats and becomes chronic, it can lead to disorders such as an anxiety disorder.
Anxiety disorders are characterized by excessive and persistent worry and fear about everyday situations, which can lead to negative health impacts such as impaired immune system function and an increased risk for heart disease. Steph's inability to employ adaptive coping strategies and her tendency to focus on potential negative outcomes suggest her stress response may be maladaptive, contributing to an anxiety disorder.