Why am I breathless with heart beating hard? I walked across my school campus, I don t know how far, but it was pretty far. Then I sat down at a bench. My heart was pounding hard and it made me feel breathless. When I inhale, my lung has this asthma-like sensation of my lungs feeling scratchy or irritated (I also have asthma but I don t have it at the moment). Or it kinda feels like my lungs are expanding too much, or some kind of stomach bloating, it feels like I could burp. Also, 2 days ago, I had seen my doctor for stomach problems that wouldn t go away. My father had GERD/gastritis stuff and I have it too. She had me get urine and blood test and an xray, and she gave me famotidine, 2 a day. I have no known allergic reactions to medicine. I m feeling a little off but I also get very anxious when something happens to me.