This is such a heartbreaking song. The lyrics are basically telling us about the true feeling of heartbreak and missing someone that you loved so much. When someone falls in love, they put a lot of time and effort into making the relationship work out. And in the process they get really used to that person. They are dependent on them and need them in every situation. This song is the perfect depiction of that. Lewis says “You’re not here to get me through it all”, and that literally makes me cry because he is saying that love makes all the pain go away.