difficulty breathing, burning in sternum, bloating

i am 21 years old and had no problems like this before, the only stomach problem i had was nausea after eating fatty foods..
ive been having problems starting 5 days ago. Starting with difficulty breathing, could not take a deep breath, and felt slight sensation of burning in lower sternum area. second day the breathing problem left and i started having a burning stomach. a heavy burning sensation in the upper stomach nearing the lower sternum area, the breathing problem at this point was almost non existent. i went to ER they did a blood test it came back normal, and prescribed me famotidine. the pills seem to have no effect, but the pain would leave randomly, sometimes came back after eating, sometimes not. I feel bloating sometimes, heavy bloating to where my stomach felt full and couldnt eat, and sometimes not, yesterday the pain was almost gone and everything appeared to be somewhat normal. Today i started having heavy breathing problems again and a heavy heartburn sensation in the middle of the sternum, as of right now it is only a heavy burning sensation in the middle of the sternum. So it was mainly breathing problems at first, then mainly burning stomach, then burning lower sternum, sometimes mixed with difficulty breathing(the breathing is usually the first symptom i experience), and heavy bloating, now im at burning middle sternum on the 5th day. my stools are fairly normal with diarrhea, i might add that my symptoms have been progressing and evolving, this middle/upper sternum heavy burning sensation i did not have the past 4-5 days. Once i get hit with a symptom (burning or bloating) it stays for the good part of the day...
Im wondering what this is specifically, i am very stressed and anxious, but im thinking this might be due to low stomach acid not high, so in term im actually making the problem worse...please tell me what to do