I went to doctor because of i can't get breathe when wind is strong. she took x-ray and listened my lungs she said you are ok. what's my problem?

Workup is not done!: The most common cause at your age would be something called exercise induced asthma. These attacks usually occur when exercising of in cold weather. A good history-taking is often enough to make the diagnosis. Failing that, there are specialized lung function tests which can help. Inhalers used before exposure to cold air or exercise help greatly in these cases. Good luck!