From what my sis says (who has had multiple MRI's are her back) say that spot on your lower back that is more black than white (I think around L4 or L5) the disc is probably bulging and not herniated.
If I were you try and find a good chiropractor. Avoid surgery at all costs (my sis wishes she knew about the chiropractor we have now before she had all her back surgeries) also avoid physical therapy if you can, some of those exercises can make the pain worse. I have had p.t. for my back as well and did not get any relief in fact my pain got worse. It was not until I saw this chiropractor (my fourth) that I am now feeling better in not just my back but neck, foot, and knees as well. good luck, achilles2