See doctor. Its very important to be evaluated. Severe chronic pain usually takes multiple doctors and many months of treatment to resolve.
See a physician. There are many causes for foot pain and this coupled with the fact that you mention this being chronic, I would recommend seeing a specialist to have your cause more fully evaluated.
Have it evaluated. Your pain could be as a result of many different things. A thorough history and physical exam and possibly some laboratory and radiology exams are needed to determine the exact cause. Causes of pain may include: trauma (fracture, sprain, arthritis, tight shoes), infection, metabolic conditions (gout), musculoskeletal or biomechanical abnormality and neurologic conditions (neuropathy).