Q: How do I recover from “haven’t used it much and therefore losing it?”

You say you’re 60+ and experiencing vaginal dryness and painful sex. Usually the solution at this point includes localized estrogen. You mention a family history of breast cancer, which is not a contraindication for localized estrogen; we actually use it with breast cancer patients themselves. There are also two very effective non-estrogen prescription options: Intrarosa and Osphena. The laser treatment offered with Mona Lisa Touch is quite effective as well. 

Once there is pronounced atrophy and pain, which it sounds like where you are, the use of moisturizers, lubricants, and vibrators typically are not enough to regain comfort. Used earlier, before atrophy is pronounced, they are effective in maintaining comfort.

I hope you explore your options with your health care provider! Regaining this part of life is important for so many of us.