My interpretation of the song is someone who has had enough with life and wants to kill themselves but is afraid of coming back because they dont want to deal with life anymore.
"But you can't break my heart.
As long as I can be myself, I'll never fall apart."
That part says that they have some self confidence left but
"And you can't take me in.
If I'm not broken, break me down,"
is them saying that they dont want this confidence and asking for someone to break it
My interpretation of the song is someone who has had enough with life and wants to kill themselves but is afraid of coming back because they dont want to deal with life anymore.
"But you can't break my heart. As long as I can be myself, I'll never fall apart."
That part says that they have some self confidence left but
"And you can't take me in. If I'm not broken, break me down,"
is them saying that they dont want this confidence and asking for someone to break it