Maybe you aren't communicating enough during sex. Unconditional love is most often associated with mother love and not romantic love. Romantic love is almost always conditional because you have rights and responsibilities in relationships. There are romantic notions of falling head over heals in love with your soul-mate. We want someone who will take the responsibilities of taking a relationship seriously.
Romantic love is always conditional.
It is much easier to see the difference looking back on a relationship. Lust doesn't last long and there is a terrible insecurity about it that you want to possess the person and you want them to make you feel good. Love is less driven and you realize the person is separate from you, and you can feel secure when they are out of sight that they still love you. If your husband is impotent and you are masturbating, then your sex life is being kept alive. He needs to see a doctor or therapist as soon as possible.