Suggest Treatment For Shortness Of Breath And Anxiety

I took a fall on my right butt and leg muscle and ended up on my back. About 4-5 hours later I felt that I couldn't breathe. I went to Er and they told me it was anxiety. My heart races all the time and it becomes worse with activity. Any thoughts? I have a CT Scan with contrast and an x Ray of my chest. The doctors are telling me that it's anxiety or allergies which I don't believe.