Love Marriage Or Arrange Marriage?

Hi Friends, I am 25 yrs old Hindu Rajput Girl. I belongs to a very good family. I love a guy a lot & we both wants to merry. But that boy belongs to OBC Caste. Caste does not matter for me but for my family it matters.I am having an affair with my Boyfriend from last 4 years even we physical many time also. He sometime having an affair with other girl also but now he is not in relation with any other girl. He promised me for that he will not do this type of mistake again in future. He are happy with each other. Now we wants to marry with eachother but our family is completely against us. He is well settled & doing govt job in Railway & I am doing job in Reputed Travel Agency. We both are financial strong & settled. We both want to marry with each other. We don’t want to go against our parents but live separate with each other. Please tell me should I get marry with that boy or do arrange marriage. If I do arrange marriage it will difficult for me accept someone else as a husband because I love him a lot. Please suggest me what can I do? How can I convince my parents for my marriage?