Before you know if you have to leave with this for the rest of you life, I believe you definately have to see another opinion and if you need third and so on... Most of us went and go through this for years, and a good, knowlegable Spinal ortho and a good PM Dr are the key on determened what is exactly wrong with your back.
Don't hesitate: if you in pain, something is not right and that is why second and more opinions so important.
I agree with you on painful discogram. I had my second one 2 weeks ago and it flear up my pain so bad that i doubled my PM since.
I wish you to find the answers for yourself and feel better!