How Can Foot Pain In The Ankle, Knee And Thigh Be Treated?

I have flat feet, I know that. I wear insoles in my shoes from Dr. Scholls to Walkfit. My problem is the pain I get from it. My ankle kind of hurts, my knee and thigh even more going up to my hip and testicle. I've had a problem with drug abuse so my doctor won't give me any strong pain killers and right now it happens to be on the left side but it can be both. My left hip, groin and testicle all the way down to my toes hurts moderate-severely. Its been like this since I was a kid and no one knows what I should do other than wear insoles! PLZ help, Thanks, Joshua