Your past is made up essentially of two spheres- things that happened to you and that you experienced, and things that you did which affected others- either beneficially or negatively.
When considering who you are, and the baggage that you certainly carry around with you from these two spheres of the past, it may be helpful to remember that while these two parts of your past indeed shaped you, shaped your experience, and your outlook on life- they are not you. They are a part of you, no denying that- but there is a potential higher self which incorporates these parts and yet is not limited by them, nor is defined by them. I write potential, because without awareness of this, and a lot of effort, then the past may end up devouring your present, as well as consuming your future.
Your past- all that happened to you, all that you have done- they are inside your experience, but they are not you. The ever-unfolding present and all its possibilities does not need answer to them. Merely acknowledging them can keep them in their place- the past, and allow you to be free of their grasp on the present. You are more than the sum of your experiences, your mistakes, and your failures. You are more than the sum of your wins, your triumphs, your successes as well. You are an ever-changing, dynamic being in a constant process of creation, destruction, decay, renewal, and your ability to redefine yourself in the face of everything in your past, despite your past, and thanks to your past, is one of your biggest potential strengths.