At this point you need to give her space and work on you. I highly recommend reading Not "Just Friends" by Shirly Glass. It will help you get to the reasons why your relationship got to the point of you choosing to cheat and hopefully help both of you understand the other better.
If you're not getting anywhere in counseling then I suggest looking for another counselor.
Bottom line, if having another child is a deal breaker for either one or both of you then it's time to move on. Every child should be a wanted child.
If you love somebody, set them free. http://tinyurl.com/2empx2g