Woooah.... Cool it bud. You may have overdone it. Look from his POV. Someone whom he taught to "love Jehovah" is now talking crazy shit. You want to keep the lines of communication open, hoping he will see the truth. After no time at all, he sends you emails that are thousands of words long, basically repeating themselves. Whether you agree or not, clearly his brain is infected with demonic apostate teachings and he must be cut off.
I know it's harsh to say, but that may well have been what's happened here. An active JW ONLY wants to keep the lines of communication open just enough to help and "encourage" the person. If that person tries to infect you with their apostate diseased demonic teachings, you must protect yourself and cut him off. It's the only way the WT can retain such control over its members.