The Desperate Things You Made Me Do Lyrics

Lyric discussion by suclid003 

Cover art for The Desperate Things You Made Me Do lyrics by Magnetic Fields, The

At first I thought this song was about someone who's depressed and wants to end his/her life (hence the "you don't even like anything you like or the people you know and all of your reasons to stay alive died "), and the song is being told from a very close friend who had to do everything he could to stop this friend from killing him/herself. But then I thought that it might be simply about a lover who screwed him over. Does my initial interpretation make sense? And also, I don't get how this is tongue-in-cheek. The lyrics seem serious; is it simply the fact that he's stating that he wants to "beat someone black and blue?" Or is it tongue-in-cheek for being excessively emotional in tone? Because I don't see that being the case.