You say you were diagnosed five years ago with fibroids, and you've reached menopause (one year without periods) quite recently. The good news is that fibroids tend to shrink in menopause, so they're unlikely to be causing the soreness you describe after deep intercourse.
The less good news is that your symptoms sound most consistent with vaginal atrophy, the typical consequence of the absence of estrogen in the vagina. I'd recommend that you start using a vaginal moisturizer or vaginal estrogen as soon as possible. The moisturizers are readily available; you'll need a prescription for the estrogen, which comes in a variety of forms for local application.
What you're experiencing is normal and easily treated—more good news!