Continue to back way off and let him be. Let him make his own decisions, for better or worse.
Do some 180's - what have you not validated him on in the past? Validate them now.
Also, try to really listen to what he is feeling and needing under all the blather - it's not so much what you say, but if you can truly try to see things from his perspective, and continue to ask "Tell me more about that ..." kind of questions that open him up to do his own talking, he may calm down a bit.
