I don;t know if this will help, but when my anxiety was at it's worst I would get sensations of shortness of breathe, but I noticed that if I took a deep breathe it felt fine. I tried breathing normally, and had no problem. It was just the feelign of shortness of breathe. Coincidentally, when I figured this out the feeling occurred less and less. From what little I know, anxiety can take on many forms. It can seem like stomach issues, heart issues, lung issues, and even head issues. I experienced them all. If you really think the lungs are the problem, get them checked out. I've heard of people that have "slight" asthma and don't know it. And they got it cleared up with minimal medication.

I dont know,i dont wease I dont cough wich are classic symptoms...

Again this is only what little I know.. Lol. You may not have the full blown symptoms. The slight asthma, will seem like nothing at all, but in fact may be present. If it persists, getting it checked wouldn't hurt.

I don't cough much apart from when I have a cold and I can't hear any wheezing in my chest. But the doctor can, with a stethescope. When I exercise even moderately I often have to stop for a few seconds as my chest seems to tighten up and walking and talking at the same time often leaves me just a little bit out of breath. Cold air, stressful situations (arguing? Shouting?) and smoky atmospheres make my lungs feel itchy and again my chest seems to tighten and of course my heartbeat goes up as I struggle to get a decent breath.

I have had late-onset asthma (ie diagnosed as an adult) for 12 years and I would suggest that if any of these symptoms sound familiar to you, don't dismiss them as merely 'anxiety' but get them checked out as - a factor not often recognised by the public generally - uncontrolled asthma can sometimes be fatal. At the very least, getting your symptoms under control should help you get back to exercising again!