Anxiety over cheating husband

So mid March I received a message from my friends husband. It seemed a bit fishy and I was confused. I messaged him back asking him what’s going on, and he told me my husband cheated on me. Which is very odd because my husband only met him once. I asked with who!?! And he said his wife( my friend) I was lost with words....I didn’t know what to do. I wanted time to stop, and me just vanish at the moment. My heart shattered...I’ve been with my husband since I was 15 and we got married and now have a 2 year old. We’ve been through so much together, and I trusted him. Supposedly they both didn’t go through with the sexual act because it didn’t feel right. But til this day i don’t know the details of what exactly happened. Seems like that doesn’t matter right? Well for the past two weeks I’ve been having dreams over the situation. In my dream I confront her ask her to tell me what happened. Or i hit her or him. I’m trying to forgive him. I was going to leave him, but all i thought about was my daughter. How much more precious her heart is than mine. And we can work through it. However, I have so much anxiety when i wake up. I don’t know what to do. And he seems to now understand. Because it wasn’t done to him. I feel like it’s trauma or something. I need some advise ladies. These nightmares are EVERY SINGLE NIGHT. It’s like i can’t run away from it..

*also I’m pregnant, found out recently but got pregnant before i found out about this act.