Chest pressure, numb arm, no relief.

A few nights ago, I noticed some dull ache in my chest and arm, it was not painful or sudden and came on slowly. The second night I experienced the same thing, but it had escalated into terrible pressure and numbness on my left side. It was so distressing and I was so overwhelmed I became hysterical with fear and had a full blown panic attack. It passed within a few hours and the chest pain subsided. Last night, same thing. My mother and I decided to take a trip to the E.R. just to be sure. ECG, chest x-ray, blood work, everything came back fine (I am an active 26 y/o female) and I was treated with something to calm me down and sent home with anti-inflammatory/pain killer. Tonight I felt as if something was tightly wrapped around my shoulder. My chest and left arm have this sensation of swelling although there is none. I started to lose it several times tonight, and I continually remind myself that I am healthy, and it is not what it feels like. It's so hard to ignore, it is so uncomfortable, it is frightening. The anti-inflammatory had no effect, I cannot sleep and I have a hard time sitting still. I plan on calling my doctor first thing in the morning, just a few hours from now. Any advice on what to do in the meantime? Has anyone felt this before? This is the worst feeling.