My wife had fusion of L4, L5, and S1 seven years ago, from deteriorating disc problems. Surgery was a big success, pain before surgery was excruciating. One is key was giving 100% effort in Physical Therapy as soon , directed by doctor, as possible. A lot of data available for daily walking with a purpose routine benefits strengthening lower back muscles, which takes much stress off lower back. Will pray for for your condition and decision.
Pass the "Sportsman Baton" on before you're gone, promote values for others to hunt and fish upon.