"The more I reflect, the more I think it was just residual sadness and the memories of the past that hit me. How ugly it was. "
Maybe you are finding a little gentleness and compassion for yourself. Sadness for the very, very hurt Mish in the car... Understanding her pain, wanting to comfort her, no way to do so. Except you can tell her inside yourself what you wish she'd known then, and give her a hug.
Really. Yeah, I know, sappy. But we need compassion for ourselves just as much as we need it for others, if not more. Understanding our own pain, our own weaknesses, our own faults lets us forgive ourselves, and then extend compassion and forgiveness to others.