I Am 59 Year Old, Obese Woman, I Do Not

I am 59 year old, obese woman, I do not exercise and lately have been sweating profusely with even mild exertion like housework, changing clothes in my air conditioned home, sometimes also have nausea. Could this be my heart or just a result of being do heavy and out of shape. I am 5'5, 274 lbs. I have no chest pain. I'm on Crestor, Venlafalaxin and Bupro piano meds.