The wild JPMorgan Chase sexual harassment scandal has gotten even uglier ... because the female exec at the center of the explosive lawsuit says she's now being bombarded with rape threats, graphic sexual messages, and harassment after her former subordinate accused her of abuse. Lorna Hajdini says in new court docs, obtained by TMZ, that her life has become a "living nightmare" since the allegations went viral online ... and now her lawyers have filed disturbing emails she allegedly received