Your lower back is a different problem, bulging disks can hurt like mad, they can press on a nerve, which would cause the intermittent loss
of function you've experienced. If the brace and
physical therapy didn't help, you can see a neuro or orthopedist about getting it operated on. This will provide enormous relief. They can do a CT scan of your low back, which is cheaper than an MRI. Even a plane black and white X-ray is better than nothing, and that's really cheap.