There is the truth that meets between reality and conscienceness. Your actions, your conscious desire to forgive, are real but the realm of sleep is a playground for that which wants to undermine us from our waking desires and impulses to be good, to do what is right. If we let it do its job, we end up doubting ourselves.
I don't speak from theory. I was good because I was told to be good. And, I believed the world was good. Then I learned it wasn't always good. Next step - how to behave and feel the truth of who I am and how I felt. That was no easy task and I felt like I was faking it.
Yes, that was the word I used too. Interestingly, I still feel sometimes as though I am a fake. Case in point: I never cried after my mother's death. This means I didn't really love her. Ergo - I'm faking it. Of course, that's pure bullshit.
For me, the solution to middle of the night obsessing was and remains prayer. It is very common for me to wake in the middle of the night filled with worries, fears, anger, doubts, and dread. I finally tried prayer - the Hail Mary and Our Father of my youth and adult life. They act as a meditation, a mantra, a chant, a redirection of thought. My belief in their power restores my trust, my faith in what I really believe to be true about myself.
There is no one who pushes my buttons more than my husband does, and like you, the event is almost always about some little thing. And again like you, more than a few fights ensued because of the provocation, with rarely an apology (well, on his side anyway). But, I chalk that up to male pride and I let him have it. But somewhere along the line, I learned to let him know my real feelings and my hurts and/or general disagreement. It's not easy and I've learned to pick my times so emotions of the moment don't clutter things up.
I find myself often feeling fake at work and the source is clearly my burn-out, my impatience with the same questions and attitudes I've dealt with for 21 years. But, self-awareness has taught me to recognise the slide into rudeness and impatience (well mostly). The extra effort to reach out, do good, help and give guidance always, 100%, results in gratitude because someone took the time to listen and to hear.
Of course, there is always a voice waiting to tell me I'm such a fake. And it's not just about faking forgiveness, either. Learning to trust your own realness, in all things, just leads naturally to believing in your capacity to forgive. To not believe in our self only weakens us.
Of course, the stronger the self-belief, the stronger the assault from outside to undermine that belief, that understanding of our self. We find ourselves meeting and learning and coming to know and understand the religious sense we are all born with. But that is a whole other conversation.