Lower Back Mostly Upper Right Buttock Pain. Pain Radiates To

Lower back mostly upper right buttock pain. Pain radiates to right thigh with burning, ongoing for 3 years(every since my hysterectomy, robotic surgery done above cervix still have my ovaries). I have been going back and forth to orthopedic doctor, physical therapy, different pain meds. Currently I am on Gabapentin 3 times a day, but was told to up the dosage so I take 5 a day with no pain relief. I have been told numerous diagnosis(sciatic with arthritis, lumbar radiculitis, sacroiliac nerve pain). Had a mri done which has a mass in the pelvic area, awaiting an appointment to have a vaginal ultrasound done.