To me, the song is about a deeply cut pain that just won't go away, something that nags the hell out of you, and drives you to near insanity, and it slices into you at random moments, never at a consistant pace that burns out after a week like a broken heart, but something that really cut deep. Something that has to be silence to preserve normality, but no matter what you do to shut it up, it will be with you for your whole life, you can try to shut it out with hard drugs and liquor, hoping you'll kill the pain by killing yourself with that shit, but when you wake up, you're still back down beneath the undertow.
and yeah, I've read interpretations on this song, this is what it feels like to me, because this is what I was listening to at the time of said event, and it made sense to me
