I love him but now I am hurting him. Am I wrong ?

I am a Kerala Christian. I am in love with a Hindu guy who is 2 years younger to me. We are very happy together and I am sure he loves me much more than I love him. He can keep me happy all my life and has a great family who will accept me. I feel he is the perfect guy for me. I love everything in him. I have tried explaining my dad about this once and but he was very hurt and said he would lose his name in the society. I did not want to take any steps. But my bf came up with ideas to convince and we tried doing something. But I could not dare to tell at home. Now I am about to get engaged and he is very hurt. He tells me everyday what I mean to him in life. He doesn't hate me even after all this. Now I am having to talk the one I am getting engaged to and thats hurting him more. I told my parents that I don't like the guy they chose, I told them you don't want him in life, but they are going ahead with this. Now all preparations are done for engagement and most of my relatives know about it. I don't want to hurt my parents. What can I do ? He is very hurt and says that its very difficult for him to live with the feeling that I am going with someone else. I have made up my mind that I will go ahead with what parents said cuz its too late. Am I wrong ?