Rib cage pain!

Whitney
For the past month I had mild lower left rib pain and even said something to my OB on my last visit... As the month went on I am now in EXCRUCIATING pain, same location, lowest left rib... I know it's not the baby kicking it because the pain is local, constant and preventing me from sleeping. I don't know what to do, I've tried stretching, laying on either side or flat on my back. If I sneeze or cough, take a deep breath I greeted by this insane pain!! 
Anyone else going through this? What did you do for relief?