I Have Joint And Muscle Pain. My Left Ankle Swells

I have joint and muscle pain. My left ankle swells occasionally and I'm getting varicose veins in my arms and legs. I am taking phentermine. However, I'm a hairstylist and stand all day, so it's very common to have these symptoms regardless. My doctor basically diagnosed me with fibromyalgia from my trigger points and fatigue. All my blood tests came back perfect and they ruled out RA from a hand x-ray. I guess my question is, what exactly do you think is causing these symptoms?