Thank you kansikuvapoika, it took some time but i did read all of the ones you recommended and i liked them. If you have any more, please tell me.
It's been awhile since I read most of these, but here are all my Supernatural/Eating disorders bookmarks from Ao3. I'm too lazy to read them now, so I don't know how much they deal with eating disorders. Read the tags before, because some of these deal with lot more issues than just eating disorders.
http://archiveofouro...rg/works/502545 It Hurts, But It Works. "If Dean weren't so weak, they wouldn't be here in the first place. If he weren't so stupid and useless, then maybe he would've been good at something without needing to starve to get there."
http://archiveofouro...rg/works/722850 Hunger. "Dean stays at a friend’s house for a few days. He doesn’t like the uncertainty."
http://archiveofouro...rg/works/850728 Pointe Grise. "Dean is 12 when he is admitted into the conservatory to practice ballet, and 14 when Alastair takes him under his wing."
http://archiveofouro...rg/works/188382 Lost My Light. "Dean's most reliable relationship has always been with his own self-loathing."
http://archiveofouro...rg/works/910231 Meat. Jimmy Novak wants meat.
http://archiveofouro...rg/works/437400 Missing The Instruction Manual. Dean has anorexia or something like that.
http://archiveofouro...g/works/1471696 To Drift. High school AU, Castiel has ED.
http://archiveofouro...g/works/2089365 Veggie. "Two weeks after Cas turned human Dean starts to worry. The ex-angel is having trouble eating and can't keep anything down. He's starting to lose weight and Dean doesn't know what to do."
http://archiveofouro...rg/works/862469 Coping Mechanisms. "Pre-series. Everything blurs together, after a while: schools, towns, hunts, emotions."
http://archiveofouro...rg/works/818442 Afraid to Fly, Afraid to Fall. "Dean wakes from a nightmare to Cas sitting on his bed. His only comforts are that Cas won't tell Sam about it, the toilet he retches into, and the bottle of liquor on the bedside table."
http://archiveofouro...rg/works/879676 Nobody's Business But Mine. High school AU, Castiel has binge eating disorder.
http://archiveofouro...rg/works/879836 A Great Potential. "Alastair tells him that he needs to stop eating certain foods if he wants to get as pretty as the adult dancers."
http://archiveofouro...rg/works/717658 Red Paintings on a Porcelain Canvas. High school AU. Castiel has a lot of problems and I think he was the one with ED.
http://archiveofouro...rg/series/41743 The Mute!Cas Verse. Fallen Castiel with lots of issues. This is long and depressing. I haven't actually finished reading this yet. I think that only the first part deals with eating disorder, but I'm not sure.
http://archiveofourown.org/series/9363 Mirror. Jensen Ackles has bulimia. Maybe the best eating disorder fic I've read. I had totally forgot this, because it isn't tagged right. If you only read one of these fics, then read this.