I, too, had rheumatic fever as a child. Now, at age 62, I have been diagnosed with multiple myeloma, which is cancer in the bone marrow white blood cells. A symptom is bone pain. Your bones are all through your body. This kind of cancer depletes the calcium in the bones, causing pain and bones are at risk of fracturing. I would suggest having tests to check cell count, and protein level in your blood and urine.