eclipse: I am moved by your strong and stable character. What you’re going through is gehinnom. It’s probably the worst parents can go through with their child. B”H, I never went through anything similar to that. I do have an ex-friend though who is going through something similar. (As a side note, the reason I dropped him was because it was spiraling out of my control and I had to leave go. A friend is not a daughter and it wasn’t totally my responsiblity to see that he come back.) I do know that they tend to blame everything on the parents, rebbeim, neighbors… Anyone but them. They are sure that they have a right to act in this manner because they were “terribly mistreated”. Now, happens to be, my friend did suffer a lot at home.; abusive mother etc..Nevertheless, he ruined HIS life because “it’s their fault”. Really, I think going OTD is somewhat of a mental illness (it is usually triggered by emotional stress/disorder). Think of her as a sick child. She is pretty much incapable of loving you because at this point, she hates herself! She needs your care and love. AND she needs your discipline. It’s YOUR home and you have every right to stick to your rules. I read a about a mother who’s son went OTD. One day, he demanded a TV (which was totally unacceptable in their home). She refused. He threatened that he’ll leave his home. She went out and bought a new linen set, lamp, curtains etc. and fixed up his room. She put a note on his pillow, “To my dear son: I’m sorry I cannot give you what you asked for. But please, please stay with me! I want you to live with us. Love, Mommy.” He never mentioned the TV again, and B”H is now frum.
May Hashem give you the Koach to deal with it, and may your daughter as well as all OTDers come back to their roots.