Getting into some more familiar territory here! It's important to remember here that Prentice was taking a lot onto his own plate, despite not being alone; it's not that he doesn't trust anyone, but more that he's still working over things after what happened to him just over a year ago. He is relying mostly on himself and it's wearing him down. It takes him to the point where it harms not just him, but also Sohrab, and he's still going to be dealing with that.