Constant Leg Pain Constant Leg Pain. HELP!!?

Constant Leg Pain. HELP!!? - constant leg pain

I'm 20 and I constantly have pain in my leg. The pain feels like growing pains, but even worse. The pain starts below the knee and keep on my feet. I see the doctor and said I had RLS, but I was on several medications, but none of them worked. I have also made several attempts, but they showed nothing. The pain seems to worsen with a lot of standing, movement or exercise that requires many movements of the legs. So that a problem has been 3 years and have not found a doctor who knows what is wrong. Please help me!