In addition to the above posts, sometime sitting up and leaning forward helps (if this is your gall bladder).
Did anyone check your pancreas? Do you have a history of drinking alcohol?
Is there any blood in the vomit or diarrhea?
If you cannot keep sips of water down or you are lightheaded (dizzy), have an ambulance take you to the ER, even if you have to go to a different one to get worked up.
Did you get your liver and gall bladder checked out?
Right quadrant pain is usually from the liver and gall bladder.
As you have had vomiting and diarhea and your stomach results show up as having an irritation, it is likely that you may have a stomach bug. Have you checked out for Helicobacter Pylori and any other parasitic bugs? You do not need to answer of these questions, it is just something to think about.
Make sure that you do not eat any fatty, fried, spiced foods and lay off the bread, cakes, biscuits. You may be OK with dried toast and arrowroot biscuits. Go on a bland diet and keep off all junk foods and processed foods. Try eating mashed potato, pureed apples.
Like SassyLassie mentions, drink lots of water, diluted fruit juices, but in small sips throughout the day.
Get back urgently to your doctor so that he can arrange further tests that they have not done yet.
This sounds very serious, I am very surprised that you have not been admitted to the hospital. My aunt had your similar symptoms, they kept sending her home, it turned out it was her appendix and it was in the stages of rupturing. I would go back AGAIN to the ER and insist on more test and even being admitted, you can not go on like this.
Until you go back to the ER, make sure to take sips of water to help stave off the dehydration. Again, I can not emphasize enough, please go back to the ER, those symptoms are NOT normal, you need help, ASAP, make the doctors listen, do not leave even if they tell you it is nothing.