Feeling confused

I found out last weekend that my husband was cheating on me. He wasn’t seeing this girl face to face, but he was talking to her through snap chat. They were talking for 2-3 weeks and I had no idea. She was sending him nude pictures of herself. And he said he didn’t send her anything or hook up with her. He didn’t come out and tell me I found out from the girls mom and brothers. The girl happens to be my husbands ex girl friend. She had cheated on him and left him and then we got together. I confronted my husband about it and he admitted to doing it. He said he doesn’t know what was going through his mind at the time. He thought things were rocky between us. I’ve thought everything was fine. He told her that if he wasn’t with me he would “totally” get back with her. We never really fight or argue. I’m just lost on what I should do. We haven’t even been married one year yet. So this is a bit concerning to me.

I am having trouble getting pregnant due to PCOS I was diagnosed with in October. I asked him if that was why he did this behind my back and he said no. I love you and we will get pregnant someday and have a beautiful baby.

I’ve confronted this girl about this and she said no it would never happen and if it did I would have told you. But obviously she’s lying to me.

I’m just so hurt by this and don’t know what to do. I give him credit on telling me. Would of been nice to know sooner and not from other people. I made him block her on every social media site he has. He’s since deleted Snapchat and Instagram.

Just a lot of trust has been lost. I guess I can forgive but never forget. Just want an outsiders opinion on this. I bring it up....because I have unanswered questions and he always says....I’m sorry for doing it but can’t we just forget about it. I always say NO because I’m so hurt by what he did.

Any suggestions or help would be great. Thanks!