TumbleBug, your situation sounds unusual, even when compared to the diversity of patients in this community. Though you've had some pathology since age 14, the rate of recent changes you describe sounds concerning. I'd like to know more about what you recall from 1998 that might be relevant to your spinal health. Do you really think carrying books could have caused this? Our bodies are tougher and more resilient that this!
Have you seen doctors that are not specialists, but look at the whole person's health? E.g., DO, ND, functional or integrative medicine doctor? If you have a systemic problem, an orthopedic fix might only address part of the problem. It just depends on where the pathology manifests; locally or systemically.
Does this thought process make sense to you? I hope it does! I have more questions, as usual, but don't want to drive you crazy. More later.