Diagnosis?

I feel like I'm whining, and that's definitely not what I want to do.  The surgery seems to have cleared up the initial disc problem, but apparently something else has gone awry on my left side.  The pain has been pretty much non-stop, with good days and bad days, good nights and bad nights, since my first experience with a urinary tract infection, keeping me from feeling good.  Having taken the tapered prednisone prescribed by my doctor, I waited another week to see if the pain would subside, and it didn't, so I called him on Tuesday.  I went in for another MRI on Wednesday morning.
I'm not thrilled that I had to undergo another MRI, which is like having 500 x-rays taken, but I DO want to know why I have so much pain in the left side of my back, which radiates throughout my entire left hip area.  I'm not claustrophobic, so sliding into that narrow tube didn't bother me; however, laying on that table caused my back to roar with pain.  By the time I was slid out of the tube, I had tears in my eyes because the pain was so bad.  The nurse had to help me sit up.  I now have to wait until next Friday, August 5, for me to see my doctor and get the results of the MRI. 
In the meantime, I've tried to increase my walking distance and went about half a mile with my husband last evening, after dark, when it was a mere 90 degrees outside, a considerable drop from the high temperature of 102 that day.  At least the sun wasn't beating down on us!  When we were heading back to our house, I mentioned to Bob that my back was hurting, but it didn't get any worse, and I slept well until around 6 AM today.  Within an hour of rising, however, my back burned and throbbed with pain.  Even taking 2 pain pills did not take away the extreme discomfort, although it did take the edge off the pain after about 2 hours.  I wonder if walking so far had anything to do with it.  There's no way to tell, I guess, unless I do the same thing some other evening.
So I'm trying to manage the pain while I wait for next Friday to be told what the MRI revealed.  Whatever it reveals, I pray that it doesn't require surgery.