Why do cough, nausea with occasional vomiting, loss of appetite, and constipation occur?

Hi doctor,

I am a 32-year-old female and a mother of two children. I have a diagnosis of Hashimoto, lichen planus, and vitiligo. I have had 11 years of chronic medical stress over my 11-year-old daughter, who has CHD and had four open heart surgeries and a cancer diagnosis five years ago. Before six years, I started having strange GI symptoms, and I was so sick that I landed in the hospital on IV fluids for four days and was then released. The gastroenterologist did an endoscopy and said it was a hiatal hernia. He said that it was small and would not cause symptoms and also told me it was related to stress, and it seemed less concerning. I have dropped from 178 to 145 lbs in four months unintentionally. I will list other symptoms with descriptions. None of the doctors I have seen seem to think there is anything wrong with me.

I have a cough and thick saliva that becomes worse in the morning. It is so thick that I cannot swallow it or breathe out without gasping. It gets better but is still present throughout the day. I have a noticeable flushing redness on my face and chest without exertion. My heart flutters or feels like it is pounding really hard at rest. At the end of the day, I have nausea with occasional vomiting and loss of appetite. I feel constipated; however, the stool is soft and thin, and sometimes diarrhea. I do lots of straining, excretion feels incomplete, and I go multiple times to the bathroom yet feeling not done excreting. There is a darkening of the skin around my mouth and under my right eye. I also have random dizzy attacks feeling as though I will faint, followed by sudden nausea and tingling hands. I occasionally have sudden blurred vision and uncomfortable feelings in my kidneys. I also have pressure or fullness feeling in the pelvic floor and rectum. I have a rash on my hip that looks like ringworm, and I was treated for it for five weeks, but it did not change and did not spread. I also have complaints like excessive dry mouth and thirst. These symptoms have crept in one after the other over the past year. My thyroid function is within range, and I have had laboratory tests like endoscopy in which a hiatal hernia was found and gastric emptying slow but not paresis, Hida normal. Abdominal ultrasound was also normal, with no pancreas view. Please help.