Have you examined your expectations about sex? How realistic and fair are they?
Is your spouse on medications that could help explain the lack of sex drive?
Is it possible your spouse is siphoning off his/her desire for you in other areas (e.g. pornography, masturbation, workaholism, lust)? Have you discussed that with him/her?
The sexual state of your marriage is often a thermometer of the rest of your marriage. How do you two resolve anger and keep it from leading to bitterness? How can you take a step in the direction of resolving those areas of bitterness?
Is your spouse a victim of past sexual abuse that he/she may not have fully dealt with?
Have you told your spouse how his/her choices make you feel? Do you respectfully communicate to your spouse what makes you feel secure in his/her love?
Do you pray for your husband regularly?
Are you a student of your spouse? Are you immersed in learning what pleases him/her most? What have you learned?