What Causes Persistent Lower Back Pain After Spinal Fusion Surgery?

I m losing any quality of life I had. I m 2 mos. after my 2nd back surgery (7/27/16). I m fused from L2 thru L5. I didn t think this last surgery would help (L2 & L3), because the chronic pain continues to be in the lower back (center, right & left). Everyone has said give it time. I went to 2 weeks in patient rehab, and am still going to out patient rehab. The pain is pretty constant. The nerve pain, however, does seem to be gone. Should I try and see different doctors? We live in a semi-rural area, not very close to major medical facilities.