Dean is a construction of the impact our society has on manhood. Although his troubles are partly to do with what he's gone through, the pressure to be a man and not a bitch has led to self-hatred and denial of a part of himself seen as unacceptable.
Sam: "So what kind of thing likes virgins and gold?" Dean: "P." Sam: "You know, it's comforting." Dean: "What's that?" Sam: "I died for a year, came back, and you're still not funny." Dean: "Shut up, I'm hilarious." - Supernatural "Like a Virgin"