I have pain from feet to shoulders, lyrica (pregabalin) prednisone oxycodone vicodin percocet klonopin lyrica (pregabalin), no help at all, i was told to see pain management doctor, why, what could they possibly do for pain?

They are experts: Once the pain becomes severe and chronic they have other procedures such as spinal cord stimulators or even intrathecal morphine pumps if all medications in adequate dosages fail.

A lot : Looking through the list of medications you posted, there are still several classes that have not been tried. A pain specialist can help steer you toward these other medication classes as well as offer injections or other interventions as needed depending on your specific diagnosis. Also, a pain specialist can refer you to other multidisciplinary treatment options.