Thank you for writing this. It caused my heart to ache. We experienced something similar with our 13 year old daughter who stopped eating. it was the worst 6 months in our lives, mostly because it wasnt logical. her decisions made no sense.
Same as you, with care, support, exploration, and boundaries (we really didnt impose any previously). And no, your kids are not you, and may not be fill the ideas you have for them when they were young. They are their own people, and need to be treated as their own person.
Now she is 18, she is truly healthy, curious, and is traveling in Europe and working on farms with people from other countries. She is funny, and we love being around her.
Big hug.