Hours after the fact, knowing full well she wouldn't understand a word of it, I walked into C's room and I apologized. I apologized for yelling at her, I told her that she was perfect, that I had been in pain and took it out on her, that it wasn't fair, and that I was sorry. I told her that I loved her more than anything in the world.
Again, she didn't understand a word that I said. That doesn't matter. What matters is what she DID understand: she understood that I'm her mommy, that I love her, that I came into her room and held her and read her a book and turned on the light so it wouldn't get too dark in there. She knows that I love her, and she feels that love every day. She understands that.
I feel better now.