Almost too obvious to me that this song's about a guy masturbating to fantasies, or at least fantasizing about a girl and feeling down when he realizes that she doesn't feel the same way about him. I don't think there was ever a mutual relationship. It's about unrequited love. The lines similar to "ready to blow" and "then it all just came out" imply that he's masturbating to these fantasies. It could also imply that he told this girl his feelings for her, believing that she felt the same based on those "200 things [he] took the wrong way".
Almost too obvious to me that this song's about a guy masturbating to fantasies, or at least fantasizing about a girl and feeling down when he realizes that she doesn't feel the same way about him. I don't think there was ever a mutual relationship. It's about unrequited love. The lines similar to "ready to blow" and "then it all just came out" imply that he's masturbating to these fantasies. It could also imply that he told this girl his feelings for her, believing that she felt the same based on those "200 things [he] took the wrong way".