What Does Pain Around Shoulders And Chest Post Treatment For Abdominal Infection Suggest?

About 2.5 weeks ago, I went to my physician with severe lower back pain, abdominal bloating, vomiting, weight gain...they treated me for an abdominal infection and referred me back to my gastro since I had my gall bladder out in September 2014. At the same time this was going on I had pain in my upper right arm, but thought I just strained it or somehow pulled something. Since that time I have been back to the doc for my right upper arm with the pain as it has gotten worse. They did an xray...not a bone issue that they can see. Had an MRI Saturday, no results yet. Thrown up several times and can t eat much. Pain has moved into my shoulder and shoulder blades and can feel it in the right side of my chest. Hurts to breath (like I ve had the wind knocked out of me) I don t want to be paranoid, but I don t want to be stupid either. Don t know what to do.