Very thoughtful. And thought-provoking. Yes, first-born. Yes, fairly strict upbringing. Yes, a father she's always trying to please. Jeez, I'm feeling a little guilty right now. But thank you.
Don't feel guilty. ALL girls want to please their dad and dad's SHOULD be strict! Sounds like you are a great father. None of us are perfect parents....we do the best we can and hope our kids get through. ALL of us have to deal with problems concerning our children at some point or another.
This may sound dumb, but I react the opposite of most people when I get upset or depressed: I can't eat. No appetite. Has your daughter been depressed? Break up with boyfriend?
Hang in there!
Well...it's not too late to do something...
Take a look at different ways of interacting with her...Make her feel more accepted and loved by you. Lower the bar just a little bit on her. She is trying to please you so much that she's not taking care of herself.