He says he cant be affectionate

My husband use to be very affectionate. All while we were dating, and engaged and for a while in our marriage. During the past year he has become less and less affectionate. When I asked him about it, and explained how important it is to me, he said that he can't really be that way anymore because of his ADD. I asked him why he had no problem holding me before bed, or cuddling with me before. He said that he was never able to sleep or relax, and that it was always this way.. he just hid it. I try to be understanding and put it into perspective, but I find myself being hurt a lot. What can I do?