I'm thinking gallbladder as well. DH had the same thing and apparently it's more unusual to have the pain present itself in the upper back like your so it took 5 trips to the emergency room to figure it out. The surgeon said by the time he got to it, his gallbladder REALLY looked bad. Hopefully it's NOT your gallbladder (not trying to freak you out!) But I agree, any pain that severe should be taken seriously. Please schedule an appointment with you doc or go to the nearest emergency room if it gets really bad.