DU, You have to understand his train of thought...it's on one track and that track is a loop right now. All he thinks that will save him and set him free from all of his troubles and pain is a divorce. He is not going to stop talking about it. It's like to brass ring that you try to grab when on a merry-go-round. The more he senses you are upset or that he can trip you up, the more he's going to talk about it. He's hoping to wear you down to the point that you'll say "yes, let's get this done".
You've got to be strong here and know that you are in control of your own destiny. Do not show this man your fear. He needs to see a strong woman that can stand up for herself and will do whatever is necessary to protect herself.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
