There were probably many factors that kept the relationship going and kept your love alive. There were all his promises. "I promise this will never happen again." You believed him the first time. And the second. As the abuse continued, he became increasingly remorseful, his promises more insistent. You continued to believe him; you wanted to believe him. After all, you loved him.
Then there were all the apologies. He seemed truly sorry. You forgave him. Now, however, when you think back, you realize the apologies were conditional. They blamed you! "I'm sorry, but if only you hadn't..." They always made his abuse somehow your fault. You may have begun to believe this, and you may even remember apologizing to him. You began to believe that if you were careful about what you said or did, you could prevent the abuse from happening again. As the abuse escalated over time, the blaming became more obvious. "I didn't mean to hurt you, but if you just weren't so [stupid, ugly, careless, dumb, etc.], this would never have happened." Time after time you were made to believe that every act of violence or abuse was your fault. Day after day you were made to feel that you were unworthy of him.