And when it came to killing the man in the woods, he had very little choice.
I don't think he was going to shoot himself to protect the other man.
Also, if he had been watching child porn, why was he originally going to refuse to rob the bank?
As for why he was going to shoot himself, teenagers commit suicide in real life unexpectedly for unknown reasons, especially if they have emotional issues or are victims of bullying or even cyberbullying.
He was either going to go to prison as a paedophile