What Causes Pain After SI Fusion?

I had SI fusion on Dec. 23, 2014. I am in more pain now than before surgery. I wear a bone stimulator four hours @ day. I take hydrocodeine, Advil, Aleve almost daily for pain. I try not to take the hydrocodine so much. The pain comes from the area of the Sacro illiac fusion (3 screws) around to the groin area. It does not go down my leg. Getting out of sitting position is most painful. I cannot be on my feet more than 30 minutes. Do I need to see a neurologist. I ve been to orthopedic, neuro surgeon. Steroid injections do nothing. Help! YYYY@YYYY