I am a lawyer who does some plaintiffs med mal work. I can tell you that there is no way that I would take your case on a contogency or for a fee. The primary problem that I see is that you have not followed your doctor's instructions by not getting fills. In my opinion you would have no chance to win.
Find the money for fills and odds are the band will start working for you. Hell, I find that the money that I am saving in food more than offsets the cost of fills.