I don't know that your son would be receptive, right now, to any books or other support suggestions you might offer him. As difficult as it is, it might be best to simply back off for the time being. Let him figure out, for himself, whether his dad is truly the victim, here. The more you try to set him straight, the more resistant he is likely to be.
I have several good friends who spent a few years during their kids' early adulthood unfairly estranged from them. In most cases, the relationships healed in a few years. I know it feels terribly unfair, but for some things time and experience are the best healers.