You have to keep being reminded that either both of you are innocent or both of you are guilty, a lot, because you have been severely programmed to perceive contrary to this. You think what you do to others has no effect on you, and what they do to you has no effect on them. In this there is injustice and unfairness and mistreatment and victimhood. This way of perceiving has to be gradually eroded and corrected so that you can come to believe and recognize that it simply isn't worth condemning someone because, you know only too well, that your own peace has been lost along with it.
And so this really means that you need to also learn to value peace and love within yourself, toward yourself. Without believing that you are worth loving, you aren't going to see the vested interest in loving others as yourself. You'd maybe rather maintain hate or justified anger for a while because you think the feeling of hating and being angry is actually good for you. You like the rage and the attack and the sense of helplessness, provided someone else is suffering at the same time, so you can convince yourself you're at least not as guilty as they are. But its a losing battle. You have to forgive yourself so that you can learn your worth and value and lovability, otherwise you're not going to want to protect it at all costs.
Once you do establish, to some degree, that you deserve the love of God, and you want it and value it, and your valuing of the truth has been corrected enough, you will start to experience a kind of automatic yet different response to others. Instead of maintaining condemnation at all costs, you'll start to feel that you know better, and that you know that you don't really want to feel like this. You want to feel the peace and love and forgiveness that your own heart deserves. And so even if you get mad at others, the more you forgive and learn your own innocence, the sooner you will feel a kind of growing urge to forgive them sooner. You will lose your taste for the fight and will gradually develop a greater willingness to want to put down your attacks and admit to responsibility and move into truth, simply because it is more valuable to you.
Eventually you will cease to judge, condemn, criticize, attack or project blame or anger onto anyone, solely because you've become very clear that YOU do not deserve any of that. And you also realize that truth is shared and wholeness is equal and you can't access love without sharing it with everyone. There is a oneness to it. The rules that apply to them must apply to you. As you do unto others, you DO do unto yourself. So now you have shared interests. And in your shared interest, it's in your best interest to treat both yourself and others with love and innocence and acceptance and peace. And you'll just decide you no longer want to enter into conflict or separation. And then you'll just remain at peace.
I say some of this because I understand it theoretically makes sense. I am not by any means loving all the time or at peace. But I have begun to notice a growing unwillingness to maintain angst for a long period of time. There is an increasing ... something, in my mind, which nags at me a bit more loudly, a kind of knowing, a surrender, a willingness, that reminds me of a mutual truth. And as I work on surrendering to truth and love and healing this certainty increases and speaks up more loudly. I find myself wanting to forgive sooner, just because I don't want to keep being unhappy. It takes practice. The mind needs to undo all of its ego conditioning of separation and blame and that takes a while. But slowly I see the results of a continually clarifying alignment with Holy Spirit. One forgiveness at a time.