If that doc told you you're be FINE by having a fusion, he's LYING!!! You will STILL have the scar tissue plus MORE. Not only that, but after having a fusion, levels above and below fused levels have a tendency to become unstable, and bulge or herniate and you end up right back where you started! Plus, surgery is NOT an answer to pain. Surgery only corrects mechanical problems. It NEVER corrects pain 100%. Many times you still have the same pain or worse. You're just lucky if you're pain is relieved.
So he did you a disservice by telling you you'll be "fine." You're never the same after spinal surgery. i've had 2 and I'm not the same person I was. God bless and best of luck with whatever you decide. Peace, Lee