He probably does care about you. And he most likely appreciates feeling loved and cared for. But yes, people with ptsd do have tendencies to isolate, detach, become numb when overwhelmed (see cup illustration). Even though to the supporter it is easy to see only benefits tothe rrelationship. But to him it can be exhausting and an added stressor that affects other areas of his life indirectly. Its so very hard to know when to stand firm by his side and when to let go. I have struggled with that as well. After having my heart crushed several times I have finally learned to follow his lead. If he isn't interacting, don't push. It only adds stress and does the opposite of your intentions. It will be the opposite of everything you heart tells you to do. It will hurt. But if you care about him follow his lead, even if it means letting him go for a while