I'm so sorry. This is extremely stressful. When you get through this tunnel of extreme and completely understandable suffering you may feel better if your daughter goes to a sleep clinic. This is a sign of narcolepsy or other sleep disorders, which we now have excellent treatment and meds for. My husband was Dx'd with a form of narcolepsy and with his medication, he is a new man. Successful, lost weight, confident, happier, empowered.
Whatever happened and however you work on this, you are a good mother. Only a good mother would feel as you do.