Cancer: https://www.fanfiction.net/s/3172588/1/Dancing-in-the-Dark
https://www.fanfiction.net/s/5186774/1/To-The-Bone
Homelessness (Dean): https://www.fanfiction.net/s/4783268/1/I-m-Barely-Holding-On
Deaf Sam: https://www.fanfiction.net/s/8961001/1/Your-Hand-In-Mine
Depressed/ Self Harming Sam: https://www.fanfiction.net/s/8335500/1/All-The-Lonely-People
Suicidal Sam: https://www.fanfiction.net/s/6648280/1/After-You
Abusive John: https://www.fanfiction.net/s/4833058/1/Soldier

Hope these help :)