Stomach, lungs, heart? i cant tell what it is..?

Rather than keep dropping in at the ER, you should set up an appointment with a gastroenterologist. The ER is really only to treat bad things so they stabilize not deal with some more chronic things on a long term basis, nor are they set up to do some of the diagnostic testing you will need. Does sound like GERD and possibly a hernia. You may need a swallowing study, possibly an upper GI as well. Your best bet for diagnosis is the GI team.