2 week wait for upper gi endoscopy and in severe pain

Had frequent pain under my right rib for years. GP suggested possible gallstone sludge. Have GERD and occasional dyspepsia. Occasionally also felt that rice was stuck in my windpipe.  Am obese. 2 weeks ago developed daily pain under right rib, severe loss of appetite, nausea. Admitted to hospital and checked by scan for gallstones. No issue and discharged with gastritis diagnosis, routine endoscopy and biopsy and warning about risk of stomach cancer and ulcers. Found out that referral has been upgraded to 2week wait, have complete loss of appetite, nausea, weight loss and severe pain under right rib.
Am deeply stressed, told endoscopy likely to be next week or week after but feel strongly in myself that gastric cancer diagnosis likely due to severity and number of symptoms. Am struggling to manage anxiety.