I found detachment for me was not allowing my AH active use affect me and doing and being by myself. I also felt that I was not IN love with my husband, I'm not sure I am, but I do know it is not my fault for the distance and resentment that developed in our marriage. I learned to be alone, to do things alone that I wanted to do, and stop focusing on HIM because that always seemed to do NOTHING and cause more resentment and , for a lack of a better word, hatred. My AH has moved out and I'm not sure about my feelings of love for him. I care for him and probably ALWAYS will, I never EVER want anything bad to happen to him, but that is not in my control. They make their choices and unfortunately after years of dealing with the lack of judgment, there tends to be alot of negative emotions that build in the relationship.
Prayers and hugs. Stay strong and know you are not alone in this.