I am 18 years old, five foot two, and 190 pounds. I was laying in bed and my heart rate went to 90bpm. I then left for the store. When I returned a little over an hour later, i laid down for twenty minutes because my chest really hurt. I checked my heart rate again and it has risen to 114bmp. I am in a lot of pain in my chest, feel shortness of breath, and nausea. What should I do?