Freeman, I did something very similar to my son who was about 23 at the time. I picked a different hill to die on though. I picked the blood medical treatment doctrine. I wanted to be sure in my own mind that if he decided to die rather than receive blood medical treatment, he did so after I had dome my best to instruct him of the error of the practice.
I wanted to be sure if I ever stood over his casket it was not because I had failed to educate him about the blood policy and about the publishing corporation that issued the directions. It has all worked out for the best. I valued him and his life more than I valued my relationship with him. It's a gut wrenching choice for a father to make. It's a choice few but Jehovah's Witnesses ever need to face.
I had my confrontation with him over 8 years ago. He has gone with them and stayed with them. My other sons have become closer to me and the void is filled. My life is full and I still do not regret my decision. I wish it could have turned out different, but as a father I had an ethical duty to inform my son when he placed himself in harm's way even if that information ended our relationship. I calculated it all out before I did it. I figured, either way I lose, but one way he might gain and the other way we both lose.
I hope it all works out in a good way for you. Thanks for sharing the experience. GaryB