I don’t get scared easily, but Kothanodi had me watching through my fingers. It has four vaguely connected stories, and two of them are very fucked up. There’s a decent amount of infanticide and other atrocities inflicted on minors, so be warned if you have any childhood trauma.
Also by the same director, the movie Aamis is about cannibalism acting as a replacement for sex. It’s pretty fucked up as well.