Also I have fibrocystic breasts, and I have a breast mass since May that I didn't notice before. I've never had a mammography. Night sweats at the age of 51 is usually a sign of vasomotor instability caused by decrease of estrogens. But anxiety can give night sweats too. The most effective cure of night sweats is use of estrogens.
Some women find relief in meditation or yoga exercises.
You have, as far I can see with these data, a standard risk of breast cancer. One in 12 women acquire breast cancer during their life time, a quarter of them before the age of 50. It is uncertain but possible that long-term HRT does increase the risk somewhat. Classic symptoms are waking up at night and difficulty sleeping, hot flashes, and irritability. There are some non-estrogen substances which provide some estrogenic activity, but if the symptoms are severe and unrelieved by these substances one would usually consider going on some type of estrogen replacement to improve her quality of life.