Have you asked him in what ways are you being "cold" to him?
You probably didn't say anything "wrong", don't automatically think that H's behavior is because of you. I sense something else is going on too, but we are going into assumption land if we speculate and jump to conclusion trying to connect the recent dots. Whatever it is that's on his mind will manifest sooner or later, so keep your ears and eyes open, and prepare yourself for the worst (though I don't think the worst will happen), and we'll hope for the best.
