Betty still practices vaginal penetration at 88. Your vaginal lining thins as you age. All you need is to use a plant-based hormone cream (like Betty) to maintain your vagina.
They call it post-menopausal zeal.
It's never too late to learn how to bring yourself to orgasm.
As we age, everything becomes different and that includes our genitals.
Everything you've described sounds pretty average so not to worry.
At 40, your body is changing and will continue to do so especially during and after menopause.
Her work is breath-taking.
You might consider getting an electric vibrator to increase the stimulation on your clitoris during masturbation and with your partner sex.
Get a vibe and follow the instructions for Betty's Rock 'n Roll orgasm technique.
Get hold of your anger and tell the arbiters of fashion and what's considered to be sexually "hot" to go to Hell!