What can I do about my shoulder?

I somehow injured my shoulder (not sure if it was from working or working out).... anyway, the pain is severe. It hurts to carry objects even a child could carry (like a gallon of milk), and it just downright hurts to move at all. Nothing seems to help. No medications (even narcotics) have helped, acupuncture didn't help, chiropractors didn't help, and the most frustrating thing is I've spent a ton of money on doctors and even saw a specialist out of state and MRI's etc.... and they don't see anything wrong. I don't know what to do anymore. I feel helpless and hopeless and I can't seem to live a normal life or do even simple things with this injured shoulder.