I feel your pain and frustration believe me do I know how you are feeling.
I've been struggling with so many stomach/digestive/reflux symptoms that some days I just want to end it all. I have LPR (laparopharengeal reflux) which it sounds like you have symptoms of: the throat stuff, and pain in back, my throat is scratchy and I cough a lot plus I have the burning pain in stomach and different spots depending on the day
It is truly frustrating. i can eat better than you but some days have to struggle to eat cereal even. I've lost some weight and am hoping to stabilize.
Anerexia can mean, CAN'T eat, not just Won't eat, so that's a correct diagnosis, doesn't mean that you are purposely starving yourself.
Doctors are at a loss with all of this I believe. so much is trial and error, and try to eliminate as much stress as you can,
also the heating pad does help sometimes, i recommend it.