He's a "Fish Out of Water" meaning he is so out of place. Singled out, strange, freak whatever I know that feeling so well.
He's sick of someone who he trusted (maybe a good friend or his one of his parents, I don't think its about a girl) That they told lies that he bought for so long and when he realizes those are all lies he is pissed and lost , confused not sure what to think about the world. He believes everyone always lies always has always will. So being so lost he feels misplaced a "Fish Out of Water"
I think its about two things.