I'm 15 years old and I've been healthy all my life. Up until about 3-4 months ago, I started getting bad shortness of breath. Like I'm constantly short of breath. I get chest pressure too. I dont think its a heart problem because I feel like its in my lungs. As if my lungs cant expand right and that it's mainly in my right lung. Sometimes I get these sharp pain on either side of my chest but I feel like they're in my lungs. Sometimes my shoulders hurt and I just dont know what to do anymore. I had a chest xray and it came back clear so my doc just thinks its anxiety. I really dont think it is. Helpp!