:( thats horrible. Try to think of where he'd go, talk to people to see if THEY know where he'd go. My aunt had the same thing happen to her (minus the abuse and break up thing...I think...) and she ran off and stayed with a lady she could trust. Hope that 'Josh' is doing the same and if you think of where he might be, DON'T let his parents know.
This is really depressing and I feel for you, I hope you find him. I'm in Maryland so Im close to N.J. Maybe he's staying with a friend or a family member out of state. Here, Delaware, Or NewYork. Wer'e all close.
Tell the cops. Do whatever you can do to the extent you can.
You seem like a good person. And that's what I'd do.
Or, if he has his cell phone with him, call him. (This is just by chance.)
I can't understand what you're going through; I live in Louisiana, and none of my friends have disappeared. Do what you have to; people have been known to take drastic measures after things like that.
Tell Johnny to fuck off.