hi there sounds an interesting problem, one can assume that by the amount of investigations you have had on hip/loer back and pelvis that it is unlikely but not impossible that the pain is originating from there, especially if you have already seem experienced physios/osteos.

with the neuro symptoms have you seen a neurologist, or had blood tests? maybe rule out any non musculoskleletal cause also has there are some disease processes which can cause your symptoms

goodluck