I think that this song could mean anything, really. It doesn't just have to be about a broken romance. It could be about anything that "let [something] fall". It could be about how when a child loses his/her innocence, the toy's perspective ("I'm black and blue,
And in love with you.
You said, you never would let me fall.
You never would let me fall, but I'm falling.") or it could be about how things like responsibility and time let someone down, et cetera, et cetera.
I think that this song could mean anything, really. It doesn't just have to be about a broken romance. It could be about anything that "let [something] fall". It could be about how when a child loses his/her innocence, the toy's perspective ("I'm black and blue, And in love with you. You said, you never would let me fall. You never would let me fall, but I'm falling.") or it could be about how things like responsibility and time let someone down, et cetera, et cetera.