My WH also had the A while I was 8 months pregnant. DDAY was the day I brought the baby home from the hospital. The OW was my friend and was in the delivery room. We have had several more children since then.
I am always a mess during pregnancy, and the deliveries are horrible triggering events for me. I understand exactly what you are going through.
During the A, I was distant and we weren't having much sex because of the pregnancy. I make more effort now to stay connected, and make sure he gets lots of physical touch since that is his love language. Not that the A was my fault at all, but knowing that I am trying makes me feel like the chance of a repeat A are less.
I would also tell him how to better love you during this time. Flowers? Kisses? Going to appointments? I would do things very different than the last time. Maybe childbirth classes? He needs to know that you need for him to lay the love on very thick during this time.
After the baby is born, I always feel so much better, and there is this lovely new little creature to love also. I hope you are able to sail right through and get to a place of happiness.