My daughter won't sleep without nursing on one breast and pinching the other with her fingernails. She'll cry for hours, and when I say hours, I mean she's been up until 6am until I, reaching my point of utter exhaustion, give in. I don't know what to do. If she sleeps and I move away, she'll wake and cry. Always. Always, always.   Early in the evenings we turn off all non-essential light to try winding her down. She doesn't get sugar or anything, ever, and I've...