Katie,
I am sorry for you problems and conflicting diagnosis just turns you around in circles.
You've basically got one shot at making this right. Going in the wrong direction or making the wrong decision is a scary thought and who's right? Who should you believe?
Have you considered sending your history and films to Mark? His fees are low enough and the peace of mind in getting opinions from the best of the best is worth everything.
GPN Artificial Disc Replacement ADR
Personally speaking, I wouldn't trust Stenum, I've heard too many and severe horror stories but I'm obviously not speaking for everyone. However, we all have only one spine and making the wrong decision which may cause a revision surgery is way too costly in terms of your health. You want to rid yourself of pain and get on with your life. You owe it to yourself to explore your diagnosis and options before committing to any doctor. Even if you do end up with Stenum, you should be absolutely positive you're doing the right thing.
Good luck, Dale