What Causes Nausea,discomfort In Breast And No Appetite?

I am 49 yr female. The past 2 months I have been feeling nauseated, no appetite, past 2 weeks some upper stomach area bloating , gas, and in the morning when I wake I feel hungry yet symptoms persist and when I eat everything is making me feel not so good. When I wake I have small burps-hiccups. My bowel movements are not normal in that they are not formed, they are soft, closer to diarrhea and small amounts. The past year, I have experienced alot of stress on my job and recently have left the position. My diet as well suffered greatly this past year. Up until now I have been healthy as a horse . Years ago I was diagnosed with Graves Disease and was treatment with radiation, then synthroid. This past August I was experiencing chest pain, shortness of breath, nausea. The heart monitor(ecg?) showed an abnormal skipped beat consistently. All my blood work, x-ray were normal. The ER doctors could only come up with possibly my thyroid meds were too high. The dose was changed to .100 mg and about 2 weeks later those symptoms went away. I have not had any blood work, tests since then and I am in the loop to still see a Cardiologist to rule out anything else possibly heart related. I am questioning now if I have actually have a stomach issue? gall bladder? Hpylori? as I still have no appetite, nausea etc as above. Some discomfort under my rest breast..muscle?