What should I do? "Husband Cheated"

To make a long story short. I found out my husband of two years had cheated on me. To make matters worst, I was 24, 3 months pregnant with our first child. He's 25 and cheated on me with his old boss. I was extremely heart broken and never saw it coming. We met in college and dated for 5 years before getting married. I waited almost a year after getting married to get off birth control. He's always been the perfect guy in my eyes and everyone else's. I mean our relationship was the type that made everyone jealous. I always felt that this would never happen to me. Anyway, fast forward some months after trying to move on with our lives and our baby is now here. I always asked him how long this had been going on but he claimed only for two months before I found out. I never believed it because I saw messages about "their relationship" and how he loves her and she loves him. Again, she's an older woman who is married with kids.....so anyway, after digging some more, I find out that this has been going on for 2 1/2 years. BEFORE we even got married. I've been heartbroken and honestly depressed since all this happened. My mom passed 6 years ago and I come from a religious family who's only advice is to pray about it. But honestly, I don't feel like he loves me. I feel like he fell in love with her. And although he said he cut all of this off when I found out, it's so hard for me to move pass this and see him in the light that I used to. I feel as if I only stayed for our child. Do you guys have any advice? Have you gotten pass infidelity in your marriage? And how do you accept him being in another relationship for that long with someone else?