Upper stomach pain wont go away (nausea/flu symptoms too)

Hi, I have been sick all month. 9/1- 9/9 Had severe nausea w/ upper stomach pain. Onset of symptoms began right after I had a sandwich for lunch. Stomach pain is 'L' shape along upper stomach extending a lil downward on my left side.

On 9/9 I began to feel a slight sore throat. On 9/13 I started to feel a lil better but it slowly got worse. On 9/19 I woke up really sick and was in bed almost all day- killer sore throat, stomach pain, nausea, warm head, warm eyes, body ache, runny nose, sneezing, stuffiness/couldnt breathe.

I've never been sick like this before. On 9/20 I went to see my doc. Even he noted that the timing/combo of my symptoms was odd. They said I didnt have a fever even though I felt like I did. He thought it might be a stomach flu and gave me Levaquin and Aciphex. The only thing that went away was the nausea due to the Aciphex. That nite my symptoms became severe. My head and face were hurting (unlike a reg headache and my face was hurting on the inside, not on the surface). On top of the stomach pain, my eye sockets were hurting and felt bruised, I felt shooting pain between my ears across the inside of my head, shooting pain in my arms, teeth started to hurt and pain traveled into gums, tongue and throat started to hurt and felt bruised by morning. I was hot and sweating from all the pain. Really, I was surprised I did not die.

Next day, my flu like symptoms began to go away but a cough started to develop. On 9/27 I went back to my doc for a blood test. I have a hyperthyroid condition and he said it's possible that it has something to do with the nausea. Throughout everything, my stomach pain still persists. Sometimes it hurts more after eating and when I take deep breaths. The whole month I never had vomiting or diarrhea.

Does this sound like a stomach flu or should I see a gastroenterologist? I do tend to get really bad heartburn/indigestion that lasts 6-8 hrs when it does occur. Im starting to worry about ulcers/cancer. What kind of tests will they do if I see a GE and will I need to fast prior to my appt? Thanks.