Im 13 I can't figure out what's wrong with me, i started having chest pains a couple of days ago n then my shoulder started hurting n now its sore all the time, i constantly have a headache and i cant even swallow down food without it hurting my back for some reason n i dnt even want to eat. I have to take short breathes because it hurts like right in the middle of my chest it seems.... Whats wrong with me???