If I keep the fact that this is from TFiOS, it reflects off of Hazel, and her whole 'grenade' saying (I'm a grenade, I'm trying to limit the casualties).
The first verse is about them being limited on time. Hazel knows she won't live for long. She isn't sure if she should give up her love for Augustus so she won't hurt him. The songs about her trying to decide whether or not she should let him go. The angels are people you can love; they come and go, and some of them make us feel special (Gus making Hazel feel like that).
If I keep the fact that this is from TFiOS, it reflects off of Hazel, and her whole 'grenade' saying (I'm a grenade, I'm trying to limit the casualties). The first verse is about them being limited on time. Hazel knows she won't live for long. She isn't sure if she should give up her love for Augustus so she won't hurt him. The songs about her trying to decide whether or not she should let him go. The angels are people you can love; they come and go, and some of them make us feel special (Gus making Hazel feel like that).