Re: Son drinking and smoking

Not sure what you can do now that he is 21 and away from your influence. It's too bad that you (and your wife) failed to raise him better and somehow have conditioned him to become as he is now. Not that you can go back and re-parent him better than you did but, you have to face it that he is a product of your parenting and how you are seeing the consequences of inadequate parenting or maybe some genetic thing that you don't mention.
re: I am struggling as a parent of 21 year old son who did everything right so far.
Response: IMO, this is a glaring example of DENIAL and DELUSION which attempts to say that the drinker or his parents is somehow PREFECT when he obviously IS NOT.

re: I want to help him, but do not know how.
response: you may need to start by HONESTLY admitting that something in his childhood is causing his need to use BOOZE to deal with his unhappiness as a child. When he said: he replied ya, dad - chill. That is a clear indication that he DOES NOT like or respect you so it's up to you to courageously face what all happened when he was little to create his dislike for you. Once you get honest about your parenting, you might have a chance to give him the love and respect now that was missing in his early childhood.