First, to be fair to your husband, take him at his word that there are no non-sexual factors affecting his desire for you. Have him examined, and appropriately treated, for depression. Anti-depressant medications tend to reduce libido, however. And he may be overwhelmed by life over the past several years, again possibly a sign of depression. If he gets an all-clear here, and there are are no other systemic medical factors, then you could well be facing the awful reality that yours is becoming a sexless marriage. It does happen, and, typically, when it does occur, the "high-sex desire" partner tends to become most dissatisfied and even resentful of the other. It can even affect self-image. Very commonly, the "low sex-drive" partner remains unconcerned about sex, and unresponsive to erotic/romantic sexual overtures from the mate. So, to help answer your question: what should you do, I ask: after you have gathered the facts, what would you like to do?