Hopeful27, I was in almost the exact same boat as you.
Together 6 years (engaged for 5 of those), since I was 18.
We are now almost 6 years out from Dday. While it is sad we have no visitation, because of OW, it is what works for us. (If you have time, you can read my profile to see what we have gone through with her).
The difference is how my WS reacted to her pregnancy. We were in R. She showed up at his (our) place of work to announce the pregnancy (the parking lot). He immediately told her the baby didn't change anything, that he still "wanted to work things out with Want2help". She told him "Let's see if Want2help wants you now!" and that she would "take him for every dome he had". But, he made his intentions/priorities (to work on US) clear to her. And THAT is why we have made it to now.
We are now married, and have a child of our own. Happier now than the 6 years previous to the A. Why? How? Because of WORK. Over a year of MC. Over a year of IC for him (and many months of IC for me)... and constant, never ending, work.
Feel free to pm me, and find us down in ICR, the OC board.