Hi, I'm 51, Female And In The Past 6 Months

Hi, I'm 51, female and in the past 6 months my joints have become very stiff and painful. It started about a year ago with my left hip, but recently has progressed to my knees, both hips, fingers, ankles and shoulders. My knees are really bad. I'm a waitress in a very busy diner and stay pretty active. My whole body just hurts anymore. My anxiety has gotten worse and I have trouble falling asleep. I feel like I'm too young to feel this damned old!! I feel exhausted. 70 year old women can run circles around me. What's wrong with this picture. Also, I'm only about 20 pounds over weight and I don't smoke or drink