6 month married

Over the course of the marriage for 6 months i found out my husband been thinking of the other woman he cheated on me with before our wedding. He cheated with her for 6 months and then married me. We been together 6 years total dating and married 6 months. I found pics hidden in his email of him and her, also a video talking and laughing both are old but he recovered it last week in his phone. I also saw on gps he passed by her job and house, not stop pass by. I asked if hes obsessed or in love with her and why he marry me.(he deny loving her or wanting her) How can you marry someone and think of another person all these months? Advice please