Trying to figure out the concept of forgiveness

I am just trying to figure out the concept of forgivenss. How am I supposed to forgive the man who was my first love who I  married and who hurt me by his abuse and violence. How can I forgive the man who abandoned his firstborn son without a backward glance. How can I forgive  a man who shows no remorse for what he did to us? The concept goes over my head! Everyone who I have worked with in counseling has told me I have to forgive in order to heal. Isn't it enough that I don't passionately hate the guy anymore? I can't say if my heart will ever be capable of the concept of forgiveness. I am trying to get there but I am not sure I ever will.