My friend can't care past a certain point...?

[jfeoaivm]

Basically he won't put emotions into things that should be worth doing. Now it seems as if he's shutting down when it comes to others. He seemed to be the loner type, likes being alone but likes to have at least one close friend to trust. But since he doesn't like to be helped in anything. Or with anything. I'm not sure if he even cares about caring. It's as if he wants to be isolated from the world and is trying to push everyone away by being apathetic. He got into a situation where someone had strong feelings for him and he tried to care as deep as they, and just couldn't. Is there something wrong? And what should be done? I understand they'd have to want to care, maybe he's afraid of emotional hurt? Problems in the home growing up? I don't know. HELP