Something genuinely wrong happened to you, and the bitterness grew because the wound never got tended. Hear this clearly: your anger about injustice is not a sin, and God hates what happened even more than you do. The hard, freeing truth is that you can hand the scales to a God who actually judges rightly, and let Him carry the weight of making it right. Releasing it to Him isn't saying it was okay. It's refusing to let it keep poisoning you.