What is happening to my disk?!

Forgive the long story...

I am a female, 27, and four years ago I was diagnosed with a herniated disk (L4/5, left paracentral). Also, I have six lumbar vertebrae, not five. To treat the resulting sciatic pain , I first tried acupunctured. Then I went to a sports medicine doctor who gave me a steroid injection into the spine, VIOXX, and several rounds of physical therapy. The injection did nothing good (it was very painful at first, and I felt no benefit in the end), and as I am wary of pills, I chucked the VIOXX after two weeks (this was before it was pulled off the shelves). Eventually, my pain lessened to the point where I functioned as usual, though with some daily pain.

A year after this, I came to China for work, and one morning (this was three years ago already) I woke up unable to move. (Though, a few days prior to this, my pain was worse than usual.) The pain was excrutiating and I had difficult to anything than lying down. Being in China, with only local health insurance, by boss took me to a traditional Chinese doctor. He totally refused to give pain killers or anti-inflammatories of any kind, and over the course of a month, I was treated with almost daily doses of vitamin 6 and 12 injections, traction and traditional manipulation "massage". This treatment was the most painful experience in my life however, it worked. By the end of it all, I was in better shape than I had ever been since the first time this condition caused me pain.

Since that episode, I suffed only occasional pain, especially on very cold days. I started practicing yoga regularly, and this got rid of ALL OF MY PAIN.

Very recently, I got promoted at work, and the consequence of this was very long hours seated in a ordinary, lousy, office chair. It also meant MORE work, MORE stress and less time for other things, such as my regular yoga practice. At the beginning of the month, I went running with a friend, and afterward, my sciatic pain starting nagging at me. A couple of weeks later, I became very uncomfortable at work (which also includes weekly flying and lots of hotel rooms), and this week I decided to take a couple of days off to see a doctor.

Finding great success with Chinese treatment, I went to the Beijing Massage Hospital. They took new CT scans and told me that I needed to cut back on all the sitting at work, and go in for a couple months, but only a couple of times a week, of traction, electro-magnetic therapy and massage. They also gave me some herbs.

The doctors told me that as I came in with relatively mild complaints, and the fact I had been in decent shape prior, I am in a good position to recover quickly. However, they told me that my herniation was bigger now, that is, WIDER (I took my old scans in for them to compare), BUT THINNER. The doctor explained the the protrusion had expanded and in the future I might feel pain on BOTH sides of my body, but now, the protusion can only be seen in two frames of the CT scan, instead of five, as it was in the scan taken in 04.

So, my questions: Are changes in herniation usual? What does this mean about the nature of my condition? How might have this change occurred, and is it a good thing, bad thing, or just a thing? Should I be concerned that my pain has returned? Could it have meant the onset of something greater? And is it possible that just SITTING has provoked the return on my woe?

I would appreciate any insight you could offer. My English-language resources are rather limited here in Beijing.