Heart heaviness and short of breath

Hello... I am a 21 year old female I have been having a heart/chest heaviness since quite a long time....

The feeling is like my heart is struggling and there is something heavy on top of it. I also feel a mild pain... or discomfort in the heart area. I have noticed that it usually comes when I lay down (in the evening) or when I sit in a slouched position. I also feel short of breath with it. I went to a doctor but they all say it's stress... and I have had an EKG and it turned okay but somehow that doesn't make the heaviness and the discomfort go away....

I am worried that there might be something else... I also have hypochondria for which I got a cognitive therapy and now it is gone... Im generally very healthy... I have smoked for 2-3 years in my teenage years but I quit long time ago... Does anyone have any suggestions of what it might be.... ?

[vienna13]

Hi, I think you should go back to your doctor and tell about that heaviness and the short of breath. EKG is one thing, they might do more tests.
Also be sure you eat right. Eat more light food, be sure don’t drink diet coke and watch the labels for aspartame, MSG, eat more small meal. If you overweight that might be one reason also.
  Good luck, hope you will get your answers soon!