Hi
Here are a few lines from a similar post on Med Help: “There are several possible explanations for your nausea (that I assume is not associated with vomiting). Your post nasal drip and sinus condition could be the cause of your problem. Gastrointestinal causes to be excluded include esophageal reflux, gastric inflammation and delayed gastric emptying. This last condition can be related to a number of illnesses including diabetes, hypothyroidism, and abnormalities of gastrointestinal muscles or nerves.
I suggest that you see an ear, nose and throat specialist. Necessary gastrointestinal tests include an endoscopy (to visualize the lining of the esophagus stomach and duodenum) and a gastric emptying study.” Refer:
http://www.medhelp.org/forums/gastro/archive/775.html
The esophageal reflux and gastric inflammation has been ruled out in your case. Your blood sugar was high and maybe diabetes is the culprit. Diabetes also makes you feel very tired. Hypothyroidism should also be ruled out.
Another cause that I can think of is hiatal hernia where the stomach protrudes into the chest cavity.
Please discuss your case with your doctor. Since there are many medical problems, a clinical judgment is required. It is difficult to comment beyond this without examining. Please let me know if there is any thing else and do keep me posted.