A Long Way Down by Nick Hornby (p. 299)

"...I had wanted to kill myself, not because I hated living, but because I loved it.  And the truth of the matter is, I think, that a lot of people who think about killing themselves feel the same way...They love life, but it's all fucked up for them. [...]We were up on the roof because we couldn't find a way back into life, and being shut out of it like that...It just fucking destroys you, man.  So it's like not an act of despair, not an act of nihilism.  It's a mercy killing, not a murder."