Is There Anything I Can Read To Help Me Understand

Is there anything I can read to help me understand my husband. He seems really cold and non concerned about me saying that I'm not in love with him anymore. We are sleeping in separate rooms. He seems to think he's still in love with me. He seems non concerned about what I have been telling him and seems to think it's just a mood swing I'm going through. We haven't made love in 12 months. I don't understand his ability to not let this affect him.