I was in pretty much the same situation about 1.5 years ago.
My son was giving his first talk, the bible reading and I was mentally and physically out but my wife and children were not out at the time. I viewed the WTBTS as a cult and that this was a major step for a JW as there would be so much love bombing given to him and it was killing me inside that, to me at least, he was getting deeper into the cult and that I would not have to work that much harder to get him out.
I decided NOT to go to the meeting and hear his talk. It hurt him and my family for me not to go but, to me, it was the better of 2 decisions as, honestly, I was at a point where I might have done terrible things there at the KH that night, things that would have "altered" my sons view of me and not in a good way. I imagined myself throwing chairs through the 2nd schools window separating it from the main auditorium.
My take on it at the time was that, compared to me missing his talk, the damage I might do during the meeting would be harder to repair at a later date.
I was between a rock and a hard spot, so to speak. I had actually thought of taking him out fishing on the boat that day and just not making it back in , in time for the talk. He was basically crushed at the time that I did not make it to his talk and others at the meeting wer talling my wife, " I can't believe XXX (me) did not come to hear XXX talk" etc,.
I went out to dinner by myself and was watching the time and was distraught at the thought that my son, trapped into a cult, due to me, was slipping through my fingers and falling deeper into the cult mindset.
After I was able to get my family out and got to the point of being able to explain my reasonings to my family and son as to why I had to miss the talk and the potential damage I would have done and the fallout from that it is now not so much as a sore spot that it once was.
He gets it now and smiles when I describe at what I might have done during the meeting that night.
I will admit that it take him a bit to get over as he would throw this in my face every once in a while and I would have to re explain it all over again.
As a side note, he recently asked me to take him on a fishing trip and my wife chimed in "If your dad takes you fishing this weekend will it make up for him not going to your first talk?" He beamed "Yes, yes!"
I said "Sorry,.. I'm not taking you fishing this weekend to make up for missing your talk, I have explained as to why I missed the talk and the reasons and by me taking you fishing this weekend to make up for it would make it seem that I was wrong in my decision to miss the talk, do you understand?" I then added " I will however take you fishing this weekend if you'd like"
Big smiles from him,.....
This act alone was probably the hardest and if I was not afraid of not damaging the building or at least controlling my anger I would have went and then just tried to work that much harder to get him out. It worked out for our family in the long run.
NJY