Dealing with teens. Am I failing? Anyone else feel like this?

dropped my son (16) off at school this morning. The son whos been quiet and moody forever. Try to play it down and not talk, then we never talk. Try to play it unphased-connect and joke about a song on radio, and he snarks back at me. Try to confront him he shuts down. Ugh!! Help.. anyone else? Now worrying. Im feeling like Ive failed him and myself. Can use someone else to talk to who identifys with this teen stuff?