Eight years ago I was diagnosed with a pelvic nerve entrapment issue and dysfunction in the pelvic floor muscles. Normal activities like sitting, walking, standing and even sleeping had grown difficult; a very active life style and a successful career came to a screeching halt. None of the physical therapists I consulted with were able to identify the root causes of my condition, which worsened with time.
I finally learned about Revolutions in Fitness, in San Jose, CA (see Doctors and specialists in the USA, California). They are staffed with awesome PTs, and they were able to identify the asymmetries that were keeping my body from healing. It turned out one of my big problems was a rotated and side-bent coccyx. After about three coccyx mobilizations my sitting and sleeping problems improved significantly. This is done internally and/or externally and while uncomfortable, is not terribly painful.
As I read all your stories about surgery my heart goes out to you and I'd like to strongly recommend you find a "functional manual therapist" located near you (check out Institute of Physical Art for a national listing). If you can't find one locally and have to travel, the staff at Revolutions in Fitness is worth the trip. They will assess your body holistically, connect the dots and thoroughly explain your situation and treatment plan.