Did you tell your husband this before you got married? If you didn't and you're just springing it on him now, don't be surprised if you get a very negative reaction. If that's the case then what you're doing isn't fair at all. He entered your marriage with a reasonable expectation of having a sex life with you, his wife. If you're changing the rules now, then you are the one in the wrong. You are correct that he is entitled to it and frequently. After all, it's not like he's all of a sudden saying, "I really hate supporting our family, so I'm not going to do it any more". You entered your marriage with a resonable expectation that he would hold down a job and support your family. It's basically the same concept. Neither of you can or should back out on the commitments you have made.
I'd actually recommend that you see a therapist for this after talking to your OB and ruling our hormonal problems. It is not normal or natural to see sex as "disgusting". Sex is a vital part of a healthy marriage. It is a beautiful and spiritual thing when it is shared between two people that deeply love each other. It's a great stress reliever too.
Some food for thought. Most of the moms that I know that get burnt out and feel like their identities have been consumed by motherhood are the women that are not having regular sex with their husbands. The women that have sex with their hubbies regularly get that affirmation of their femininity and sexiness on a regular basis and are less inclined to feel that their sense of self has been consumed by motherhood. Women that have regular sex with their hubbies also tend (generalization) to have happier marriages and also tend to have a more positive self-image. Semen also has hormones in it that are beneficial for us ladies to come in contact with and can promote a sense of well-being.
God made us as two halves of a whole. He engineered our bodies to fit together in a mutually beneficial, sexual marital relationship. It is right for a wife to sleep with her husband. There is no reason not to do it and tons of reasons to do it.
Parting thought: The more you do it, the more you feel like doing it. It's true.