Recently found out my husband cheated on me....

My husband and I were labeled 'high school sweethearts'. We have been together for almost 8 years and married almost 5. We now have a beautiful 5 week old daughter that we had both prayed for for so long. Once she was born I thought life was complete and I was so happy. Everything came crashing down on me just a few days ago. I found out that last July while my husband was back home with his family for an event I could not attend, he cheated on me. He slept with someone, someone I know and use to be pretty close with years ago and still occasionally talked too. The most disturbing and sickening thing of all, is that this woman was pregnant with another man's child! The day she and my husband fucked, she had an ultrasound to find out the gender of her baby and I sent her a message to congratulate her and she talked to me as if nothing happened.

I am completely lost and devastated. I have spend nearly 8 years of my life with this man and of course I love him but how am I suppose to make this work? And now we have a child which makes my life more complicated. I will not stay with him just because we have a baby. If I choose to stay it's because I love him and I want it to work for us, but I don't know if I can ever truely and honestly forgive him.