@socalfriend
Constant nausea is definitely a miserable condition. A couple of things come to mind when I also read about your other symptoms. Were you ever tested for POTS? Postural Orthostatic Tachycardia Syndrome. It’s not uncommon, especially in women and can include many of the symptoms you describe. Also can coexist with autoimmune illnesses. Here is a link where you can learn more about it. https://my.clevelandclinic.org/health/diseases/16560-postural-orthostatic-tachycardia-syndrome-pots
Another GI cause in addition to GERD is gastroparesis- stomach doesn’t empty normally.
Nausea can also be caused by inner ear disease.
I have had constant nausea for a year now. I’m almost certain my nausea is caused by gastroparesis or similar. I am going to have a gastric emptying study done.