i originally wrote this as a comment but aff is a confusing website so, here goes.

hoseok was not sick at first. like, they were married, but suddenly taehyung wanted a divorce (i guess bcos hoseok was always drunk and all, im not sure myself haha) but hoseok didnt want to. so he dragged taehyung to the car and attempted a joint suicide (saying that if he cant have taehyung; then no one can. -implying that hoseok was paranoid that taehyung wanted a divorce bcos he loves someone else)

but before the car crashed, hoseok softened when taehyung cried and said "you're scaring me." so before it crashed, hoseok wanted to save taehyung. (and maybe punish himself bcos he made taehyung cry, thus the reason why he stopped taehyung's body from crashing on the dashboard.) 

hoseok was in a coma for a year, and when he woke up, he was diagnosed with amnesia. he also had broken hands which underwent surgery, (most likely) and to make the healing process faster, a doctor suggested that he draw everyday to exercise his hand. and that is why hoseok likes drawing so much.

+ and the reason why he only draw parts of taehyung's face/body because his mind can only make out bit by bit bcos of his amnesia. and also, the reason why the voice in his mind kept saying "hoseok" is because it was the last thing he heard from taehyung.

sorry it was confusing ;;

i want you guys to know that i wanted to make it a happy ending but i don't know how especially because how can you make a happy ending on a story that started with divorce and attempted suicide. sorry ;;

thank you for reading + subscribing + for the upvotes ^^