The Terminally ill Extra is Healthy

After dying at the age of thirty, I was reborn as the male lead's childhood friend in a romance fantasy novel. But of all things, I'm an extra who dies young at the age of eighteen from a disease. In a novel where the male lead, traumatized by the death of his childhood friend, rejects and pushes away the sickly female lead, but eventually falls in love and lives happily ever after, why did I have to be that 'childhood friend'? It's bad enough that I die young, but I certainly don't want to inflict trauma on someone else. There's no choice. Now that it's come to this, I have no choice but to make the most of the virtues of a reincarnator. Plan A. Don't get close to the male lead. "Young ...