Calming the restlessness of the mind is achieved by Abhyasa and Vairagya.
Abhyasa: The means (practices, discipline, etc) that is employed in order to remain in a state of union (harmony) with one’s own Self is called Abhyasa. Consistent effort.
Vairagya: The highest form of Vairagya is when we are established in awareness of our true nature. When we discover that the joy we are seeking resides within us, we relinquish our attachment towards the outer.
In my understanding this means: Do the very best you can and see what happens.
I know so many people who would go even as far as manipulate, lie and gaslight someone to get the outcome they want.
If I plant, say, an apple tree and I take the best care of it that I possibly could I still have no idea if the apples would be sweet, plentiful, beautiful or even appear! I simply can’t control that. All I can do is do the best I can (abhyasa) and let go of my attachment to the outcome (vairagya). The joy is in the journey. In my effort. The joy is not in an outcome I cannot possibly control.