Hi im 18 years old and i have what has been feeling like heart pains agan, iv had them sence i was little and they come every once in a while . They last for a couple seconds but today it came out of no whear again except more painfull as ever, i realy was scared , it feels like something stabbing my heart and it doesnt allow me to breath , its unbarrible, why? What could be the matter with my me?