What are some practical steps to reduce mental fatigue and stress without completely changing my lifestyle?

How did you begin for a life of meaninglessness, cowardice and delusion? Are you a victim of multiple traumas? Does your conscience bother you when you virtue signal with such eloquent vapidity?
How do you stay calm and focused when dealing with life-threatening situations in the ICU?
What’s something that seemed complicated for years but became surprisingly simple once you understood it?