Welcome to HCM
We understand your concerns
I went through your problem description. You are correct and You know the reason also. It has to be stress
related to stress do make our body and brain lethargic and feel more fatigue
, exhaustion etc are part of that feeling. Simple body biology says to take rest when you are stressed mentally and physically. You are being physically active and naturally body responds.
Take a three day off and relax. Some short vacation should do wonders.
Hope this clears your doubts. Available for further clarifications.