That is existential nihilism.

https://www.wikiwand.com/en/Existential_nihilism

> According to the theory, each individual is an isolated being born into the universe, barred from knowing "why", yet compelled to invent meaning.

> The common thread in the literature of the existentialists is coping with the emotional anguish arising from our confrontation with nothingness, and they expended great energy responding to the question of whether surviving it was possible. Their answer was a qualified "Yes," advocating a formula of passionate commitment and impassive stoicism.