How can I fix this severe pain in my right shoulder?

Yesterday I had pain below my right rib cage and severe pain my right shoulder(just in the joint) and I ended up going to the hospital because we thought it was my appendix or gallbladder. Well they did a CAT scan, and ran blood and urine tests and everything came back fine and I'm perfectly healthy. My blood pressure and blood oxygen levels were great too. So they told me they don't know why and just to hope it goes away. My side isn't as bad today but everytime I take a deep breath my shoulder is in excruciating pain. Could the pain be from stress? I've had no recent injuries or done anything unusual but I have been extremely stressed lately. What can I do to lessen the pain I'm miserable :( Thanks.