It looks to me like there's a bit of a synapse tangle where self-assurance normally operates. He's got way too much and way too little of the same thing. Never seen a personality like his.
Doesn't seem to affect the way he is with his family, and apparently he can be quite charming. And yet - the narcissist liar is in there and so is the guy who cannot accept a contradictory word without falling apart.
One thing - I am beginning to think his brain isn't organised enough to be a tyrant. Maybe we are better off with him as a right wing president who cannot get stuff done than with Pence who is mentally stable and presumably can focus!