It looks like you are looking for "Looking Glass", a 2008 song by Canadian band The Birthday Massacre.
See the video here:
Note: my personal understanding is that the cracks are not due to an abusive relationship with the teacher, but to him teaching noxious beliefs or values (= putting nails into their heads).
Is it Count on Me (Bruno Mars)
Lyrics: "I'll sail the world to find you"
Emo --a little bit
Punk? not really
One hit wonder? Definitely not!