Enlarged heart, do i have it?

Hey everybody, I am a 14 year old male, pretty healthy (not abs) but not overweight im 5 foot 3 inches and about 125lbs. so my problem is i think i have an oversized heart not an athletes heart. the reason i think this is because my whole family has high blood pressure, i have chest pains (like stings) and sometimes have trouble breathing like my chest feels heavy. i also get random spurts of short headaches like only sometimes. why i am really worried is because my parents are out of town until tuesday and im with a close family friend at my house. my mom told me not to worry about it and i can see a doctor when she gets back but what if something happens when im sleeping etc because billy mays died from an overlarged heart. please help thanks!!!!!!!!!!!