What Causes Pain Above The Ankle And Migraine?

I m 15 year old female. I only weight 85 pounds (which I do eat healthy) and around 5 foot 2 inches. I have RA and chiblains, and sometimes get mirgrains when stresed. Lately I have been getting pains right above my ankle, and a lot of mirgrains, I als have been getting a lot of cramps in my toes and in my calf, along with somtimes my neck.I m also get black spot and dizzy when I sand up really fast. I have no clue what to do or what could be the cause of this, and its making me really scared