you should read sadistic beauty bl side story. It has kind of what you are saying
I can't remember which manwha, but there is at least one where the kidnapped guy does try to kill himself, and the other guy freaks the fuck out, nearly kills him himself, and then basically goes a fucked up straight-jacket route so the kidnapped guy cannot self-harm. Poor guy ends up just in this unconscious state feeling like the kidnapped is always there tormenting him, and very ptsd ear-ringing phantom itch scenario.
Personally I don't see the tormentor in this situation getting the awareness to change course. Mayb they consider going to hospital, but you know they're fearing exposure of their crimes too. If anything, they're more likely to attempt to bury a body then try and get them help on a full deathbed scenario.
please tell us if u remember the name
I be wanting the one kidnapped/tortured in these types of stories to just kill themselves or attempt it to the point of near death just to see the abusers reaction and it never happens #－.－)