My new boyfriend

My new boyfriend when I first met him told me he loved me and he was so nice and kind and loving. After six months he told me that although he still loved me he could not love me in the way I wanted him too. He could no longer make love to me as all he could think about was his last lover who he thought was his soulmate. He still wants me to be there for him and he is always there for me, but how can I get through to him that he has to let go of the previous relationship and enjoy us in our new relationship. His last relationship was over 5 years ago.