Space Junk, by Rory Barnes (epub/pdf/Kindle)
Earth, the fantasy: a green, storied world where mankind originated.
Earth, the reality: the junk planet, a dirty, dangerous place filled with detention camps, gangs and gangsters, flop houses, body parts factories, and a lawless immigrant community of aliens and humans.
Ned believes the refugees from outer space have been interbreeding with cockroaches the size of dinosaurs. Em, pretty and slim, is seeking asylum; she thinks that Earth is unbelievably primitive. Space Junk is a coming-of-age tale in which true love and survival don't always walk hand-in-hand!