Past is just that past and simply it is a story that you tell yourself in the now, there is no real past, as there is no real future. Only now is real all else is just a story appearing in the now.
Past, present and future as linear time is a human construction and in itself can be useful to deal with mundane things, like booking a dentist or vacations, but when it takes your full attention its usefulness fades and it becomes a limitation.
Whenever you are stuck in the past you are giving away your attention from the present moment where you can seize your life fully. Past is a story of learning that can help you in this way to evolve your awareness, but if you make it something to hold on to, it will consume your energy and restrain you from enjoying this present moment as it is.
Whatever happened in the past it is not happening now, so let go the past and act now to the best of you.
There are may be something in your past that it is difficult for you to let go, because you believe it to be part of who you are, that it defines you and the more you believe it, the more you feel stuck to it. You can choose now what deserves your attention and where your attention goes your perception of your live goes with it.
Make peace with your past, no matter how hurtful it may have been, it is over, but if you hold on to it, you are reviving it on and on. Set yourself free to live your life as it is now.
Life is simple the way you relate to it, most of the time is not.
It is up to you to make your life easier or harder and you do that by the way you perceive it, by the way you interpret what happens in your reality. For your essence it is meaningless whatever you do, because it is perfect as it is and nothing can change that. But for the good sake of this human experience it is relevant the way you perceive yourself and your reality.
No good comes if you reject some parts of your reality, because it only gives it more power over you. That does not mean that you have to like all of it, to accept all of it, but it means that you have to recognize it as it is, to learn from it and let it be.
Doing so nothing can harm you, all happens in you and not to you. You are life, all of it and not someone that is victim of life. Just seize the now as it is with detachment and all comes to place. Try it for yourself and see the results.