I'm not going to give medical advice or even take a stand on second/third/forth opinions or which type of doc you should see.
I'll just offer my own personal experience...
I've suffered from back issues since I was 20. That's 28 years now. I have arthritis in my spine and some genetic abnormalities in both my disks and vertebrae that combine to create mechanical and structural "challenges."
I've seen just about every kind of doctor out there, with many difference instances of each kind, some of whom are the absolute tops of their specialties. I've tried all sorts of things. I've had a dozen or more CT, Xray, and MRI scans. And where am I now? For the last two years, I'd say my back has been the best it's ever been since I was 19. I give most of the credit to a very sharp Chiropractor -- she's the 8th or 9th Chiro I've tried over the years. So after finally nailing it, with her help after working on it for 26 years, here's my advice for you and anyone with serious back issues (by serious, I mean disk, vertebral, nervous, or structural issues, not just "sore back muscles"):
1) It's all about your core strength and flexibility. Sacrifice everything for core strength and flexibility. Spend all your time researching and understanding the muscles and structure of your core, and how to develop strength and flexibility. Note I'm always saying strength AND flexibility. With just one or the other, you lose. Only with both do you succeed. With core strength and flexibility, everything else is possible. It is the foundation. Without it you lose. I won't tell you exactly what this means. There's millions of words out there on the net for you to find. Many on this site -- which is a great place to start.
2) Don't go under the knife. Ever. The procedures today are still as medieval as they have been for 50 years.
3) Get over the "cult of the squat." I was a member of the cult. I loved the squat. But it is just too risky a move, and it will ALWAYS find your weak point and fuck you. It is simply a matter of time. Yes it is a great exercise. But for people with serious back issues, the risks are not worth the benefits. And regardless of what the cult says, there are plenty of ways you can achieve strength and mass in your legs without this exercise. Lunges, sissy squats, and presses all can be fine substitutes and there are plenty of variations of each. This site is a great resource for non-squat legwork.