The window for surgery to help in these cases is very short and is within hours/days of the initial insult.
I've had cases (this is a very common condition) that will encourage you and others that will depress you. It's difficult to gauge what the eventual outcome will be, but constant slow improvement is a good sign.
The absolute best case was a cervical disk (neck) where all 4 legs were affected. He couldn't stand and basically just paddled on the floor to move around. It took about a year, but he progressed so he could stand and walk.
Laser therapy is potentially helpful, but I don't have any experience with it. Hydrotherapy (swimming) is a physical therapy that I've found very helpful.
BTW, your vets original treatment was pretty standard for minor disk.
I understand your and your wife's medical issues - Sandy has AFIB and RA. If you need to vent, send me a PM.
Doug