He is an absolute idiot. You were giving him a second chance where most women wouldn't. And he threw it back in your face.
I know it's the hardest thing in the world for you now, but you don't need someone like that in your life. As a PP said a few posts up, I realise this isn't how you pictured your family. But you will find your feet and be an amazing mum and one day be so glad he is gone. I find being a solo mum liberating as I can do what I want without having to deal with anyone else. Only one relationship to maintain. You want to cuddle the baby in front of the telly all day watching doctor who then have fruit loops for dinner, you can.