It started about the same way for me. First doctor basically brushed it off to therapy and poorly explained what was going on. Therapy was a joke. After a year of paralysis and intense pain, I changed health plans and went for 2nd, 3rd and 4th opinions. Amazes me how health insurance has power over doctors' medical advice. Either they are incompetent or beholden to insurance, but few ARE legit. It's tough to find the few.
IDK know about a ruptured L5/S1. My main problem is in the same spot though. Herniated disks everywhere else are nothing compared to the spondylolisthesis at L5/S1.
Just to confirm, you are saying the disk replacement occurs through the abdomen as well, like fusion?