What Causes Consistent Hip Pain Post Hip Replacement?

I filed for disability due to having had a hip replacement and 2 revisions on same leg. Since then I have had constant nagging pain.. sometimes treated with physical therapy for a possible bursitis issues- but they are only guessing and after so called treatments it never clears up-- comes and goes frequently--so pain is so constant that I can t work a regular job, hard to sit at a desk job and hard to stand and walk for long periods of time. I m very fatigued and stressed and depressed. I also have been diagnosed with abnormally high levels of cobalt chromium due to corrosion, but the extent of soft tissue damage can t be totally assessed until I have a 4th revision. Need advice about what doctors should be detailing for medical evidence of my disability to the disability office.