The act of fulfilling one's ambitions, desires, etc., through one's own efforts is

The answer to the blank space part of the question is self-fulfillment.

Self-fulfillment is a philosophical and psychological term used to refer to a state of making an individual’s deepest desires come true or being able to use one’s capabilities in a way that the individual desires.

Alternative terms that are more commonly used in modern times include self-realization and self-actualization – which refers to a similar concept as self-fulfillment.