You were taken advantage of; you fell for his whiles and pewrhaps at first thought you had found someone wonderful who loved you. Then it all changed into a nightmare.
Something similar happened to me long ago. The difference was he was only about the same age as me, my parents never found out how I was controlled and abused and beaten, and it never got to the police or court. After four years of it I ran away to the country to escape him, and because my pain hadn't been resolved as yours is going to be, I fell into almost the same trap over again with someone else!. it wasn't until many years later that I finally told my parents what had happened. It took a long time for me to forgive him or myself, but finally I realised that I did not need to be a victim. I could learn from the mistakes of the past and with God's help, start afresh.
Now after many years I can see that God has been with me all through my life, helping me to grow stronger and at peace. Now I realise those were not wasted years of torment, but a valuable education in life, and that I can feel empathy with others who are going through similar traumas.
I encourage you to stand strong in court, no matter how weak you feel inside. If you tell your story truthfully and clearly, you may save some other poor girl or girls from suffering what you have suffered. If you back down and don't testify, then you may leave him free to harm others like you have been harmed.
And don't let bitterness or anger in, or be vindictive - just tell the palin, unvarnished truth, no matter how hard. You will grow stronger by going through with it and come out a better person on the other side of the pain. Instead of bitterness, feel pity for this man who has hurt you and ruined his own life too. After all, what has happened in his childhood to cause him to become the person he is, and to act this way, I wonder. This might sound really hard, but if you can forgive him in your heart for what he has done to you, then he has lost all power to hurt you ever again. If you don't forgive, he wins, if you do forgive and get on with your life away from him, he has lost and you have won.
I am praying for you, that you will feel God's comfort and strength, and that His (God's) peace will fill your heart as you go on to a whole new life, free of the past. Go, Girlie, go! You can do it!