I am a 15 year old girl and woke up last night with shooting pains in my chest and couldn't breath, I had to gasp for breath but going that made the pain worse, I couldn't call on my mum because of this, I was also still half asleep so didn't understand what was going on, this has happened once or twice, but I really don't understand why it happens, I am about 7 and a half stone and roughly 5 foot 4, please help!