Should I get Spinal Fusion?

I need your help community. I am a 40 year old athletic father of 3. For the past 4-6 months I’ve been having lower back and nerve related pain/burning/numbness down my right leg.

After MRIs and CMG testing it was confirmed that I have spondylolisthesis l5/S1 with a pars defect. I have not done PT but I did get an epidural and it did not help. I just started physical therapy but both doctors say I may need surgery. However they also said if I wasn’t having symptoms I wouldn’t need the surgery. This leads me to believe that maybe I tackle this conservatively and make a recovery. Avoiding the fusion surgery.

However I fear that the impingement of the L5 nerve roots would have life long affects the longer I wait for the surgery. I’m wondering if I at least have 3 months of PT Time without causing major irreversible damage to the nerve. In also fearful that this surgery may cause my harm than good in the long term.

For the record, although I have back pain and the leg symptoms, I am able to work everyday and go to the gym 5-6 times a week. Although the pain, burning and numbness exists, I am able to fight through it.

I am open to all the advice out there please.