I Have Been Exercising Regularly For Well Over A Year

I have been exercising regularly for well over a year - at least 4 times a week. After being on vacation for a week with no exercise, I have experienced extreme fatigue yesterday evening (Zumba) and this evening (weights and toning) while at the normal classes. My legs started shaking early on and I didn't finish either class. I've had abnormal ANA tests (speckled) and fibromyalgia has been diagnosed but The exercise has been helpful. I'm worried that I won't be able to keep up with the one thing that helps. Also worried that it's more than fibromyalgia. I would appreciate your thoughts please. Thank you- Susan Acosta