If I could offer a suggestion, go apologize to him if you can, and ask him if you can reach out to his friend together, and insist its very private and he didn't want it shared, and regrets doing so. Im sure if the friends a good guy, he'll understand, and that might help patch things up. Otherwise, just try to be there. I think his reaction is a bit extreme, but he has his reasons, so don't try to diminish them too much. End of the day, you'll just have to wait and see what he says and does. Mistakes happen, and i hope he forgives you.