I have the exact same symptoms and was diagnosed with "abdominal pain". This is the 3rd such attack. I fasted a few months back and the symptoms disappeared so I think i'm going to try this that I found on the web:
Sensiblehealth.Com/gallbladder.html
before I go back to the emergency room. The pain is not so bad-yet.

Good luck

I have gallbladder pain and it is always accompanied by right-side headache. Usually worse right before dawn. Doctors insist there is no relation - I insist there is. Just had my gallbladder out. Let's hope these headaches now disappear.

I have had horrible headaches after eating. I also have had abdo. pain. I have been through the ringer. Seen too many doc's. I t has been going on for 8mths. now. They act like I am crazy and totally ingnore the headache after I eat thing. I have had ton's of blood work. Been given all kinds of med's which finally realized weren't helping at all. So I threw that money away. Through all of this I found I have a totally unrelated hereditary blood disorder(hemochromotosis). I also found out the hard way that I am allergic to anti-inflamatory med's. I have spent about $2,000.00 dollars on test's and med's. I knew something was wrong but could not find a dr. to help me or take me seriously. Finally about two month's ago I started losing weight (20 lbs.). I work for a GI Doc. (go figure). All of my co-workers thought I was crazy. The anesthesioogists I also work with which are my real friends were getting very concerened and started commenting on my rapid weight loss and the fact that it happened so quickly in front of my GI Dr. and that got some attention along with me insisting that I know my body and I now something is wrong this was not normal for me. About two weeks ago my stomach was killing me so I reached down and felt that area, there was a huge lump on my right side under my ribs and it moved. That is when I returned to work and the to a scheduled visit that afternoon with my GI doc. He did a stat CT scan nothing. Although for two months my labs were abnormal ANA elavated, white blood cell count up. All the while still suffering from the headaches after eating, pain on the right side of my stomach and in the abdominal are that never went away. Next the EGD (scope of stomach) and colonoscopy. Found nothing. Just did the HIDA scan of the gallbladder ordered by my GI Doc. on 4/20/09 came back that my gallbladder was virtually dead only functioning at 2%. I cried thinking that we have finally found out what is wrong. I go for surgery to have it removed and anything else removable in there (lol). It has been a terrible experience. I have had unbelievable comments and also you find out who your friends really are as well. They don't want to hear it and think your crazy too. Guess they really never were friends after all. I hope this helps anyone out there not have to get to this point to find out what to do. Also remember the Dr. works for you not the other way around. Be respectful, but it does not hurt to request and at times insist on certain test's and also refuse some of the test's. After all the simple fact that the pain was located where it was and the symptom's I was having these less expensive test's could have been done first and found the problem along time ago. Now I am going to have to pay around $1000.00 more for this surgery. The sad thing is I have insurance and it has still cost me this much, amazing.
Soon to be PAIN FREE!!!