Steve, protect yourself financially... period. You do not have to be a jerk while doing this and you can always give more later,if you feel the need. You have to figure out what you are comfortable with and fight for that. Remember after you sign the papers you have to live with your decisions.
What do you want Steve? Figure that this divorce IS going to happen and sit down and think about what you need. It's okay to voice your wants, needs and desires, because you will have to live with your decision for at least nine years. Dig deep here...
You can not change your past, but you can ruin a perfectly good present by worrying about the future.