Never having been a witness I could be totally off base here. First I don't believe in meddling in other people's marriages but when there is verbal or physical abuse it's a different story. My witness mother is going through verbal abuse with her husband and at times he threatens to divorce her! It seems to go with the territory; that many witness men become domineering and abusive.
I get the feeling that you were both very attracted to each other physically; that it's mostly about sex. I could be wrong. I was young once and I do remember but I don't think that in itself it's going to sustain a relationship if other very important things are going wrong.
You say he was shy. He doesn't seem that shy now. Was he acting with you beforehand just to reel you in? Is he feeling remorse for going all the way before marriage and blaming you for his fall?
I personally feel that you really need to think hard about this. Is this the life you want for yourself, for your future kids, for future grandkids?
I suggest continuing going to your church and pray that God will give you guidance in how to deal with this. I do believe that He sometimes places us in a certain situation, not only for own benefit, but maybe even for others who need to see the light and walk away from this coercive (what I believe) cult. We may not see it as a benefit now and I'm sure there will be many here that will think that being in a cult was absolutely no benefit to them, and they may be very well be right. But we don't always sense God working in our lives and possibly after it's all over you might see this. When I say this I'm not referring to those that have been so traumatized by the Org that it's very difficult to get beyond it.
Take care