I don't have any real advice for you, but I just wanted to send my best wishes for a speedy recovery!
My parents have both suffered from back problems since I was a child (and in the case of my dad, before I was born) - my mother broke her back whilst on roller skates (!) at my seventh birthday party and my father just had emergency surgery to reposition a vertebra that had slipped out of place and was pressing against his spinal cord. If the pain you're in is anything like theirs (and it sounds like it is, if not worse!) then I'd think you're much better off staying here and getting the medical help that you need, rather than trying to survive a move (and a flight!) back to the US. You'll likely get priority treatment, due to the severity of your case (and I don't care where you're from or why you're here, I firmly believe that the sick and injured should receive treatment, regardless of whether they've "contributed" - it's one of the major problems I have with the US, but that's another rant!), and hopefully you'll have time to recover and secure a job before November, so that your visa worries will be for naught. *crosses fingers*