Chronic Appendicitis???

For 3 months now ive had persistant lowerer right abdominal pain with Nausea and Vomiting,On/Off Diarrhea, and a complete loss of appetite. I've had every test there is it seems like. I've had blood test(CBC, Metabolic Panel, and More) I've had 2 CT Scans, 10+ Xrays one with Barium dye, An Endoscopy and they all come back normal. I've done research about Chronic Appendicitis and I know there are numerous Casues for it. The Drs keep telling me that its stress/IBS. From what i've learned about IBS it is a moving pain and other side effects come with it. I am 15 and after 3 months of Pain i am ready for it to stop. Anyone else had the same issues/Symptoms ????