How do you make a relationship work after 8 months of abuse?

Me and my fiance, have gone thru alot over the last ten months. and i love this man with all my heart, but one things that makes me sketch about being with him is that he has abused me for 8 months of our relationship. and now i am pregnant with his son. and i couldn't be happier that we are having a family. the real downer is that even though he has beat me, i have hit him and done some very mean things to him in return of him doing them to me it has always been a two way street. I'm just not entirely sure how i am suppose to make this work with him even though he is taking full responsibility for is action and is currently awaiting to be charged. but how do i fix this relationship, when we don't let what each other has done to one another affect us we are a match made in heaven. but how do i stop holding a grudge and forgive him for all that he has done when i know that he is sorry and that he loves me? he just didn't know how to express it. i'm so lost on how to make it work for the sake of my heart and our son, this man i plan to marry in 2013. someone please help im so lost on how to just let him love me instead of just pushing him away.