You've noted that your clitoris appears to be smaller, which is a normal part of aging. With the absence of estrogen, it's estimated that a woman loses 80 percent of her genital volume—unless there is some intervention. The two most effective ways to minimize this diminishment are to remain sexually active (that "use it or lose it" thing I've talked about before) and to use localized estrogen. Both help to maintain the integrity of the genital tissues.
Our intent is not to "prevent" menopause, because it's a normal part of our lives. With my patients, my aim is to mitigate enough of the symptoms of menopause to be able to maintain the sexual intimacy that's an important part of life for many of us.
More often than you'd think, a patient who thought she was "done with sex" comes to me for help when she enters a new relationship. It's possible to reverse some of the atrophy that happens naturally with inactivity, but it's more difficult than maintaining sexual health along the way. If a woman is certain that she has no interest in being sexually active, there's no negative health effect of the genital atrophy—beyond the loss of the positive health benefits of sex.