My chest hurts but everything is normal

My chest hurts, it feels tight, my heartbeat is really fast and hard, I can feel it without even trying to. The doctors sad that my blood work, urine sample and chest xray came back normal, but it seems to be a lung inflammation and gave me steroids to bring down the swelling and an inhaler to help me breathe. I am not eating fast food nor drinking soda, just water. I used to suffer from asthma and the doctors found a benign arrhythmia when I was younger. I get about 5 hours of sleep during school days and in the weekends I can sleep 8-9 hours. Any help?

[tom_h]

Sorry to answer you question with a question, but How "fast" of a heart rate are we talking?  That's important information needed to provide a comment from us.  A rate ot 120 can be a response to an infection.  A rate of 180 can mean something totally different. Can you check your pulse in your wrist and get back to us?