Atypical GERD symptoms

Sorry this is so long, but I wanted to get everything out there.
At end of December after a heavy meal I woke to indigestion and stomach pain. Began as gnawing in lower stomach then upper and continued daily. Started 10 day course of Prilosec. Had similar issue a few months before and was prescribed Prilosec and it resolved. Prior to that, about 2 years before, I had ended up in ER because in addition to indigestion, I had pain in my upper chest and left arm. No cardiac issues; stress and GERD were diagnosed.
Early January I had a telephone visit with PCP. Some food triggers, worse on empty stomach and upon waking. Not always stomach pain; indigestion with spread to shoulder and arms. Sinus-like pressure in face. Mild cough with indigestion hours after eating. Occasional hot flashes/cold sweat and overall feeling unwell. No appetite. PCP prescribed continue Prilosec; second course if needed.
After 3 weeks, still no better, so saw another doctor in PCP office. He ordered blood work and prescribed sucralfate. At the same time, I was trying to get an appointment with a doctor in the digestive health area, but was told next appointment was 6 weeks out. Finally got a video appointment with a gastroenterologist. No interest in blood work; changed to liquid sucralfate and scheduled an endoscopy for 6 weeks later. Could not tolerate sucralfate so was switched to famotidine 40 mg. 2x day.
Blood work showed high Gamma GT and elevated CO2. Emailed PCP who said since liver enzymes looked good would not normally have checked gamma GT, but would order liver ultrasound if I wanted. I have had liver enzymes show as elevated in past blood work on and off over many years. Liver ultrasound once, but nothing showed as abnormal.
Endoscopy showed small ridge at end of esophagus appeared mildly thickened, so ordered fluoroscopy esophagram. Biopsies of tissues were normal. Esophagram results were normal.
I can go for a month or two with no symptoms, but when they start they continue for many weeks. I have been on famotidine continually since mid-February. I consulted a nutritionist to get some ideas on how to change my eating habits. I wondered if the fatigue was due to lack of protein, etc. One thing she suggested is DGL before each meal and that seems to help with stomach pain.

What bothers me are the symptoms that I don’t see as being typical GERD symptoms:
indigestion pain spreading into shoulders and arms; sinus-like pressure in face and foggy brain; fatigue; hot flashes with quick wave of anxiety; feeling like I need to concentrate to breath, but having no trouble taking a deep breath or exercising; bouts of severe constipation. I have Hashimoto’s thyroiditis, but it is controlled. My latest routine blood work came back fine, including test for Celiac markers. So frustrating that I keep being told my blood work is good — but I’m not feeling “good”. Just don’t know what to do next.