A lot of us get to a point in our adult life usually after trauma, upset or a setback and ask this very question. Who am I? Why am I me? It's often not enough to just know you are. The big why.
At the forefront of any journey into self discovery I would always recommend looking back to see how far you have come. Now, if there are any sticking points or painful issues......how do you determine you cope with these. As an adult your awareness and responsibilty to yourself will guide you. The wealth of support is there, its up to you to access it. Counselling, coaching, etc.
A lot of times it isnt about getting over things, its accepting where you were at the time and all you knew in how to deal with it then was what you knew. Now, with that insight you can forgive yourself for this. You only know what you know. What did you learn from the experiences? How have they moulded you into who you are now and why are you proud of your learning. I hope now you are feeling like you belong to yourself wholeheartedly and making that connection. Life is not a destination as we will always be evolving and re-evolving, coming back to yourself on a regular basis is so important to deter any disconnect.