I agree with the other two above me - he may just be overwhelmed and acting irrationally, give him some space to process what he heard and then he'll be more open to hearing what you have to say. Don't crowd him or call him, I would maybe send him just one quick message or phone call that once he calms down you'd like to talk, and leave it at that for a few days. He'll probably come around.

having said that, if it ends up that he CAN'T talk to you about this issue after you've given him some time, would you really want to be marrying someone who can't communicate or talk things through? That's an essential part of a relationship.

It will work out the way its supposed to in the end - these are all "tests" couples must pass to reach the next step, how he reacts to this is a great indicator of things to come. I really do hope he is willing to listen!