I Have Had Difficult Breathing For 7 Months. I Passed

I have had difficult breathing for 7 months. I passed out on my first spirometry reading. Lately I have started coughing and when I do I pass out then when I come to I am convulsing. This happened yesterday at my appt with the pulmonologist. I was directly sent to the ER. Chest x-rays and CT Scans are normal, but I am not. They say it's stress but that can't physically be possible. Each time I stand my abdominal and chest muscles contract and I can barely breathe, usually resulting in my fainting. I'm getting worse and tired of the depression/anxiety stmts that are completely false....I am a very happy man. The inability to breathe stresses me out. Why is this happening? Can a doctor give me a truthful answer or are there other tests that can determine what is going on?