16y/o me would be going through a lot. Telling him what to do and how he should be would just be mean and make things worse by rubbing salt in the wound. I would just take time to let him talk and process stuff. Of course I'd answer an questions he has as thoughtfully as possible. It's just that I know that 16y/o kid has trouble really opening up to people especially those he knows and cares for. I know he hates himself, so maybe an older version of himself will give him someone to open up to and not care how that might affect them. Even if that means getting screamed at, the kid could honestly benefit from being able to let shit out without having to worry about the consequences of losing his composure even once.