I've been having shortness of breath for the past two months and it started really suddenly. At first, I was also dealing with back pain and lung pain along with a feeling of tightness. Now it's mostly just the shortness of breath and a tight feeling in my left lung. My lung X-ray came back normal and the EEG report was fine too. The doctor didn't prescribe any medicine, but I'm still struggling with shortness of breath. What could be going on, and should I be concerned about this?

Patient is advised pulmonary function test (PFT)and a complete blood count and esr.