Dear Frustrated, At this point, you don't know if the reason is physical or psychological. However, your experience is not uncommon.
Some women lose sensation after bearing a child.
More often there is a fear or other resentment that emerges as a result of childbirth or the extra energy that a baby demands. You may even feel your husband is demanding too much or not giving you enough. If so, your frustration can keep you from enjoying him. The answer is simple, but not easy. You have to start talking with him about what you feel.