Hi headisspinning,
Wow, such a lot is happening to you!
To recap, it seems that in the space of about a month, you son became a publisher, then told you he didn't want to be a jw, then told you he is sexually active with his gf? Have I followed correectly?
Teens are a volatile time, but I'd suggest the family problems may also be involved here. Certainly it's great and important that he can talk to you. Can I suggest that counselling might help him? (not elders, of course, but perhaps you could find someone appropriately qualified and experienced).
Failing that, check the library and the net for helpful books and articles for both of you. Coping with change, growing up; other peoples' accounts of transitional experiences. He has had a lot to deal with.
Also don't forget the sibling(sister?) - in my experience it's the quiet ones you need to watch!
And. . . in your place, I might leave Ray Franz' book somewhere he could see it.
Best of luck and hope you had a good Mothers Day, Retro