post-traumatic embitterment disorder
n.— «People who feel they have been wronged by someone and are so bitter they can barely function other than to ruminate about their circumstances. This behavior is so common—and so deeply destructive—that some psychiatrists are urging it be identified as a mental illness under the name post-traumatic embitterment disorder.» —“Bitterness as mental illness?” by Shari Roan Los Angeles Times May 25, 2009. (source: Double-Tongued Dictionary)