It's totally normal to wonder if fatigue signals true exhaustion—many in TMS recovery share this doubt.
It's a false alarm: your body's physical capabilities aren't depleted from doing normal tasks (unlike after, say, running a marathon). Your brain generates symptoms—in your case, pain first, then undue fatigue when pushing through—to halt what it perceives as dangerous.
Sarno explains the brain does this to distract from emotions like anger, fearing they'd harm your well-being or survival (e.g., raging at your boss could risk your job and stability). Our primitive brain also flags modern 24/7 stressors—like deadlines—as life-threatening lion attacks, despite no real danger—prompting it to keep your world small for 'safety' from these bogus threats.
With baby steps in your spare time, you can ease job stress by practicing mindfulness during work and lengthening out-breaths to deepen breathing. At home, you can do deep relaxation and mind/body techniques like journaling frustrations for a few minutes daily. TMS-wise, your job is to make your brain feel safe. Consistency rewires this alarm over time.