I am 15 years old, since I was 12, I've  been having this sharp piercing pain in my chest, but this is once in a few months. It basically feels like some organ in my chest is being clenched, or stabbed, my breaths become short too, but after a few minutes it goes back to normal. I have been feeling a little claustrophobic lately, even with much space around me, i feel heated and i get light headaches. Now I have this pain in my left arm, my veins are also more prominent in my arm too. It feels much weaker compared to my right arm, it is like i have pain in my bone and muscle at the same time.