Often i get this weak feeling in my stomach then, nausea, and i start getting shaky/weak right after. could this be from acid reflux? disease

Its possible but...: The GI tract has a very limited # of symptoms to signal its distress--nausea/vomiting, diarrhea/constipation, bloating, pain, fullness, bleeding, etc. As you know, many of these characterize ibs, but are also seen with inflammatory, infectious, ischemic, malabsorptive, and functional disorders. Directed lab work, imaging, biopsies, stool studies are appropriate in excluding non-ibs pathology.