I haven't posted in ages, and to be honest, I'm not sure what your specific background is. So, take what I say with a grain of salt. As a Christian, I will say that I know what it is that you mean. For me, it did take some time to forgive even though I did want to mean what I say in the Lord's prayer. Ultimately, however...I think I have forgiven my abuser. It doesn't mean that I am not angry for what happened, but it does mean that I have let it go.
Now, what helped me initially though was to let all my frustrations out...to express what I felt (to pretend I was talking to my abuser and say everything that came in). There were many, many nights of tears to be sure, and even now, I still am feeling the effects of the abuse perhaps.
However, what also happened (I realized) is that God (who has always been there) has actually turned this abuse into something much better than it could have been. As a result, I have developed a stronger sense of empathy for others and a much stronger determination to live the "good Christian life". By looking at my abuse/abuser as somehow a "blessing in disguise" thanks to the grace of God, I have found myself easily forgiving my abuser.
Please do not misunderstand, I am not saying that it was good for any of us to be abused, all I am saying is that what was a horrible, horrible thing has been turned into something positive with God's grace. With that realization, I find myself hardly thinking about my abuser/abuse...sometimes, I even forget that I ever was.
So...my advice is this. Try to let your emotions and frustrations out when it comes to your abuser. Then, think about it and step back at how blessed you have been to have been a "survivor." Hmm...I don't know if that makes sense...regardless, I hope you'll find peace. Whatever you do, just don't give up. Eventually, you'll find that peace.