I'm sorry your DD is struggling right now. It's heartbreaking to see our children put themselves down or tie themselves into knots.
Our DS has a tendency to compare himself to others and cries that he is stupid (or that he's stupid at whatever his task is), when something isn't going as well as he thinks it should. He becomes extremely upset and difficult to calm down. One response we've adopted is, "You're not stupid at it, you're new at it. That isn't the same thing". It seems to help. I realize that doesn't address your overall situation, but thought I'd share it in case it comes in handy with your DD.
Sending good thoughts your way,
Tam
