Hi and Welcome to Share,
There are many on this site who will see your post and have some helpful advice. I am not sure that I, personally, have advice.
But, I am terrified of being pregnant again. If I found myself in that position, I would have to take it one day at a time (or one minute to the next if that's all I could handle). I would concentrate on the things I could control such as eating healthy and taking care of myself. I would try (try being the operative word) not to worry about the things that were out of my hands.
I would want my husband to let me express my fears but yet help me remain optimistic.
I don't know if any of this helps. Our situations are very different. But, I wanted to offer something. I'm keeping you and your wife in my thoughts.