Below is a story in which a Master is telling his Disciple how to keep his mind cool & how to introspect when his mind is disturbed. This story shall also give you a lesson, how you can too avoid, being agitated in your mind & be always peaceful:
Once there was a Master in whose hermitage many disciples used to live. Once in the morning when the Master was going for a walk, he saw one of his disciple sad & in a troubled state of mind. Master approached him & asked, "O Dear, On such a beautiful day, it must be difficult to stay so serious."
Disciple: Yeah, it is so but I am unable to comprehend why my mind is so disturbed & agitated. Watching intently, the Master continued to walk.
"Join me if you like."The Master walked to the edge of a still pond, framed by tall dense trees.
"Please sit down," the Master invited, patting the ground next to him. Looking carefully before sitting, the Disciple brushed the ground to clear a space for himself.
"Now, find a small stone, please," the Master instructed.
Master: "A stone. Please find a small stone and throw it in the pond."
Searching around him, the Disciple grabbed a pebble and threw it as far as he could.
"Tell me what you see," the Master instructed.
Straining his eyes to not miss a single detail, the Disciple looked at the water's surface.
Disciple: "I see ripples."
Master: "Where did the ripples come from?"
Disciple: "From the pebble I threw in the pond, Master."
"Please reach your hand into the water and stop the ripples," the Master asked.
Not understanding, the Disciple stuck his hand in the water as a ripple neared, only to cause more ripples. The Disciple was now completely baffled. Where was this going? Had he made a mistake in seeking out the Master? Puzzled, the Disciple waited.
"Were you able to stop the ripples with your hands?" the Master asked.
Disciple: "No, of course not."
Master: "Could you have stopped the ripples, then?"
Disciple: "No, Master. I told you I only caused more ripples."
"What if you had stopped the pebble from entering the water to begin with?" The Master smiled such a beautiful smile; the Disciple could not be upset.
"Next time you are unhappy with your life, catch the stone before it hits the water. Do not spend time trying to undo what you have done. Rather, change what you are going to do before you do it." The Master looked kindly upon the Disciple.
Disciple: "But Master, how will I know what I am going to do before I do it?"
Master: "Take the responsibility for living your own life. If you're working with a doctor to treat an illness, then ask the doctor to help you understand what caused the illness. Do not just treat the ripples. Keep asking questions." The Disciple stopped, his mind reeling.
Disciple: "But I hoped you to ask you for answers. Are you saying that I know the answers?"
Master: "You may not know the answers right now, but if you ask the right questions to yourself, introspect what caused the ripples & made your mind agitated & disturbed, then you shall discover the answers."
Now here is my suggestion on how you should behave in your daily day to day life. Just follow the below two verses of Bhagwat Gita which teaches, how a person of peaceful, unwavering and undisturbed mind behaves in life:
tulya-nindatma-samstutih" (Bhagwat Gita: Chapter Fourteen verse 24)
gunatitah sa ucyate" (Bhagwat Gita: Chapter Fourteen verse 25)
Sri Krishna said to Arjuna: One who is steady in honor and dishonor; one who treats alike both friend and enemy; and who has renounced all material activities—such a person is said to have transcended the three modes of nature & lives in a peaceful state of mind.