The song means that the person is believing the person the person the song is talking about is everything to them, and somehow the song lyrics make it seem like the two people in this song do a lot of things together so it makes the "but I love what we're doing here" part stand out a little. But then the person who is saying the other person is making them sick, that person is realizing that the person they are talking about isn't exactly what he thought she was. So in the end he loved being with her, just not her.
The song means that the person is believing the person the person the song is talking about is everything to them, and somehow the song lyrics make it seem like the two people in this song do a lot of things together so it makes the "but I love what we're doing here" part stand out a little. But then the person who is saying the other person is making them sick, that person is realizing that the person they are talking about isn't exactly what he thought she was. So in the end he loved being with her, just not her.