Hi
Welcome to the forum!
The commonest causes of breathing problems, light headedness and dizziness at your age are anemia and hypoglycemia or low blood sugar due to poor eating habits generally. These can be known by simple blood tests. Disturbed sleep patterns and stress are the two other causes.
Heart problems like mitral valve prolapsed is another cause.
Other causes are claustrophobia, GERD, cervical nerve compression, inner ear problem, postural hypotension or blood pressure falling with change of position, and some endocrine problems such as an underactive thyroid (called hypothyroidism), overactive thyroid (called hyperthyroidism), adrenal insufficiency (called Addison's disease), and in some cases, diabetes, may lead to hypotension and hence lightheadedness and an off balance feeling.
There are many causes of dizziness, lightheadedness, passing out, blackouts etc. It is difficult to comment without examination. Possible causes have been enumerated for you. You can discuss this with your doctor and get yourself examined.
Hope this helps. Do let me know if there is any thing else and keep me posted. Take care!
Do you feel any pain when these episodes happen?