It’s hard to be at peace when the mind is loud. It creates situations and possible outcomes, constantly calculating and running simulations.
The mind can instantly take you to a dark place and leave there wondering about. To find peace we must be able to control the mind.
Being able to be fully aware of your thoughts and control them is a hard thing to do but a skill that anyone can learn. Learn to control your thoughts, shut your mind and be at peace with the self.