Pain under my right rib cage!

I have serious pain on my right side under my ribs that creeps down to my hip and then around to my back and up to my neck. I am a 24 year old female, 5’6” 140 lbs. I exercise 4 times a week, and don’t smoke. I have had this pain for about 5 years now, varying in severity. I will go months without an “episode” and then, always in the evening, the pain will begin along the line of my right rib cage. It’s tender to the touch and gets worse as time progresses, during really bad “episodes” I can’t catch my breath or move my right arm more than 6” away from my body. I have seen a series of doctors, and all my blood tests, endoscopes, and ultrasounds turn up normal. The usual response I get from specialists is that I’m fine, and “just stressed.” (Although 99% of the time I’m not patricianly stressed or upset.)
The best way to describe the pain is as if someone is crushing my insides with their fist, I have been unable to find any sort to relief during these times, and often fall back on heating pads and hot showers – it’s more of a mental thing. The pain lasts for about 5 – 10 hours and leaves me exhausted, and unable to go to work.
I have removed all fried foods from my diet, and most oils, candy and fat. Still, keeping a  food diary I have been unable to see any trends in my eating habits that would lead me to believe it’s food related. Who knows though, maybe I’m not looking at the right things.
If anyone has ANY suggestions as to what it may be, or suggestions to alleviate the pain I would be greatly appreciative.
Oh, the other possible reasoning for the pain is often my gall bladder – my mom had hers removed – but again all doctors have confirmed that it’s fine, I’m too young, and to stop stressing….
Thank you!