What Causes Lower Back Pain Along With Stiffness And Tightness?

I am having a lot of lower back pain. I thought I hurt by back and have been going to a chiropracter for 3 weeks and its not getting better. it is right at my lower back and it is very stiff and tight - feels like something is pulling if I even bed over. The pain is going to both my hips - left side is worse and down my front legs. it feels like someone is blowing up a balloon inside of me and putting pressure on my hips. The front of my thighs will almost feel like a burning sensation. Sitting down adds to the pressure, which is hard because I have a desk job. not sure if its my back, or hips, or something more?