I'm wondering also how I developed asthma, was it 2nd hand smoke? I think it's best to avoid all smoking and pollution. I'm trying to get tonsil surgery also- does it help? it seems the tonsils and adenoids secrete chemicals that might make lung disease worse?
I very much doubt that your “troubles breathing” are related to your weight. There are many causes of shortness of breath with exercise, including but not limited to asthma and COPD (the COPD unlikely in a non-smoker, even one exposed to passive cigarette smoke). Second hand smoke could aggravate many lung diseases causing shortness of breath, not just asthma and COPD.
Given that you have taken a first step and had physical examination of your chest/lungs by your doctor and a chest X-ray. I would recommend that this is followed by pulmonary function testing (PFT).
The symptom of “breath won’t go down into my lungs” raises another possibility; that is, that you might have obstruction of one of your upper airways as can happen with inflammation, tumors and, most notably, malfunction of your vocal cords as occurs with a condition called Vocal Cord Dysfunction (VCD), this condition often suggested by abnormal values for breathing-in seen on PFT’s.
Good luck
Oh and also I have been for chest x rays and been prescribed inhalers and nasal sprays but my doctor doesn't know what's wrong! I have also had my tonsils out when I was 8 because he thought that might be the problem and he gave me a special funky purple inhaler but nothing is working! Please help!