Gabrielle,   Thanks for your question.    Chest pain can be very difficult to diagnose, especially in females and diabetics, who experience cardiac pain in many more ways than men.  However, cardiac pain is not usually associated with position changes or breathing.  These characteristics are more commonly associated with muscular causes.  But it sounds like your discomfort is quite intense and you have obvious concern.  Therefore, I suggest that you make an appointment with your primary care physician for his evaluation of your symptoms and what may be the cause.    I hope this has been helpful.  Feel better.   Martin Cane, M.D.