What does heartbun mean ?

i am fourteen years old girl. 5'7 . 124 lbs .details : i sleep 4 hours a day . and i eat nothing but unhealthy foods and i have sharp pains in my body all the time . i eat salt , and fat. but sometimes i eat veggies and fruits. hope those details help ! when my heartburn does occur i breathe in and out and it hurts so bad !