So sorry to hear what you & the family are going through. It’s really tough.
We’ve got similar mental health issues in my family (agorophobia, anxiety-depressive disorder & more).
Started when they were around 14. Since then they’ve been able to overcome this and enjoy life more for a time, but then there’s a relapse and it’s the same as before. Peaks and troughs over the years. They are now 25. As they get older the relapses are becoming more manageable. They can try and rationalize it more. It’s getting better every time. I don’t think it will ever go 100%, but it will become better.
It’s been really tough for me over the 11 years to support her and I’ve sacrificed an awful lot, but I wouldn’t change a thing. It’s not their choice, and by working with them it will get better. For what its worth, they have been incredibly successful in life- very good A-levels, social life, 1st class degree and now a solid job working with other vulnerable young people; offering help, support and referrals. They are 100% the person I am.
Stay strong. I hope that as she gets older, she will also be able to manage it better. She’s still young and has the whole world ahead of her.