I've had sex with a lot of guys, and I've come to despise them. Once I've had sex with a person, whether it's a one-night stand or a long-term relationship, I feel emotionally distanced and a bit disgusted by their body. Although these sensations decrease with time, they never completely go from my life.
Every aspect of our sex drive, and capacity to enjoy closeness stems from the lessons we were given as children. In most cases, even if the subject of sex was not brought up, children can get a sense of how their parents or caregivers feel about the subject. So how we feel toward sex, or someone's body after sex is all because of how we were brought up, and how our parents felt about the topic.
You may have long since internalized distaste towards sex. Many of us have been raised to believe that it is "bad" or "dirty," that "good ladies don't do it," that "all men are untrustworthy," or other negative views. Even inside a marriage, these attitudes might make it difficult for a person to feel completely at ease with their adult sexuality.
Take a look at your longstanding views and your focused revulsion, and spend some time understanding where they may have originated. Some of these concepts may have been created at a certain time in your sexual awareness or growth. Identifying the reason for your displeasure allows you to rationalize and rectify your behavior. Speak positive affirmations into your mind, such as "sex is healthy," or, more simply, "sexual desire is natural." Every day, repeat these words out loud until they become a habit.
Moreover, if that person you have sex with is your partner, then talking about it and opening up about the topic is the first step to fixing the problem. Take time to know what turns you off and know what turns you on in someone's body, and remember sex is consensual, you don't have to sleep with someone you feel turned off by.