The sequence of biological stress is well known. The body reacts the same to fright from the impending pounce of a tiger as it does to an insult from the bully. Alarm triggers the sympathetic nervous system that releases adrenaline, in addition to many other functions. Resistance to the bully and all that that requires depletes the body's defenses. If you stay in the resistance stage too long, the body will rebound then it's finally turned off, the body rebounds and the actual damage occurs when the stressor is gone.
Exhaustion is a full system breakdown, mentally and physically.
It demands that the stressor be removed or it will claim your life. It is usually the wrongdoer's prescribed solution for the Target. No amount of cognitive distortion or discounting will stop life-jeopardizing stress caused by a bully and her accomplices. Separation from the bully is an imperative first step. To argue otherwise prolongs the Target's misery.