You say you’re four years past menopause, and in addition to hot flashes and other symptoms, you have dryness and have had vaginal atrophy—a decrease in the size of your vaginal opening. This is a classic symptom of genitourinary syndrome of menopause (GSM, earlier called vulvovaginal atrophy). Without estrogen, the vaginal tissues become thin and fragile, and the vagina can shorten and narrow.
Vaginal moisturizers, which you say you’re using, are of some benefit. They’re better at prevention, though, started during perimenopause or early in menopause; once atrophy is advanced, they’re less helpful and may be irritating, as you’ve experienced.
The most likely effective treatment is localized estrogens (cream, ring, or tablet) or something like Osphena (oral and non-estrogen) or Intrarosa. You say you like to avoid chemicals, and I understand that; estrogen is a natural chemical, and the local application is to replace what your body used to produce naturally in the way that has the fewest side effects. Osphena and Intrarosa work like a hormone, even though they aren’t one. These are all prescription therapies, and a necessary component of your plan to counter the effects of vulvovaginal atrophy, which is chronic and progressive.
Once the tissues are healthier, you may need to use vaginal dilators to regain increased “capacity” (patency, in medical terms) of the vagina.
Whenever there is pain involved, that problem needs to be addressed first; once you’ve achieved physical comfort, you may find a sex therapist helpful if issues remain, as your gynecologist suggested. In the meantime, no one should blame you for not wanting to have painful sex!
A number of the things you say are very familiar to me: you’ve had plenty of natural lubrication and you’ve never had issues with intercourse. The unfortunate reality is that menopause changes the game, more dramatically for some of us than others. What was true for the younger you is no longer the case (ask me about menopausal weight gain!). But! I know how important intimacy is to relationships, and if you’re willing to make the effort, it’s almost always possible to regain function and comfort again.