Well, the story behind it might vary depending on who interprets it. But generally, it seems to convey the intense pain and emptiness after a significant relationship ends.
No, it is not appropriate. Such topics are vulgar and inappropriate for public discussion. We should focus on positive, healthy and respectful relationships in communication.
The amount you can quote lyrics in a story varies. Generally, fair use allows for a limited portion, but it's best to seek permission if it's a significant amount. Also, consider the purpose and context of the quote within the story.
Authors should have a sense of moral responsibility. They should focus on creating positive and healthy stories. Also, as readers, we can set our own boundaries and not be interested in any works that seem to have such vulgar content at the first sign.