14 yrs after total hip replacement and bone grafting of the pelvis still in low/high levels of discomfort every day. Exercise is not helping, ?

Pain after THR. You should see an orthopaedic surgeon to rule out infection or loosening.
Get evaluated. You had total hip arthroplasty ( w/ probable bone grafting of acetabulum) @ age 31. Probable congenital or 'developmental' hip dysplasia w/ secondary osteoarthritis or due to avascular necrosis.Either way your painful tha needs evaluation for possible loosening of components(most common esp.W/ cemented 'cups') and low- grade infection. See ors w/ hip reconstruction specialty. Good luck!