How to gain inner satisfaction?

Those people who do not care about the fruitful nature of their deed and offer their deeds to God and believe that whatever he is doing, he is meant to do it and does not bound to Karma. The person who is bound to his Karma is never satisfied. Happiness or grief; success or failure, whatever situation is there, a perfect yogi is never affected by them, because he knows that ultimately these desires or accomplishments are momentary and materialistic. The perfect yogi knows about the fake worldly desires and his Karma is surrendered to Krishna. He is never affected by disappointments and he believes in his capabilities.

So learn how to control: Eyes are to be controlled, not to be shut – as a perfect yogi knows what to see and what not. The logic to self-control is not demolishing the senses but to gain full control and discipline.

Tasmādasaktaḥ satataṁ kāryaṁ karma samācara|
Asakto hyācarankarma paramāpnoti pūruṣaḥ|| (Srimad Bhagvad Gita, Ch-3, Ver-19)

Meaning: Therefore, without being attached to the fruits of activities, one should act as a matter of duty; for by working without attachment, one attains the Supreme.

Attachment and Expectation is the main enemy of inner peace. The one who steps out from the vicious cycle of attachment surely finds satisfaction within himself.