Defining yourself seems impossible. Can there be a single thing that defines you? You may have interests or occupations that relate to you, but does that define you as a person? What, then, makes you who you are?
It would take considerable introspection to define your place in the world. Would you describe the “self” as what you believe you are or as the perspective of others? Does it matter in the end? You can not change how others see you. Then why do people concern themselves with what can not be changed? It is a conundrum to define yourself as a self from the other. So, achieving an ideal image you can never see is a plight. I struggle in this plight. At the same time, I know I am not burdened by it. Why, then, does it feel like an unachievable goal?
I can see the introspection as who you are. It also seems like an avoidance of caring. It is natural to care what others see you as. Is it necessarily a bad thing? Yes, only if it is distressing. Not caring is not natural, but it may be the most objective. If you were to be objective about yourself, what would that be? Can you come back to an objective definition of yourself? I do not believe so.
Subjective introspection it is, then. A subjective self is everchanging. So, your definition is now, in the moment. That may be your answer; it seems mine.