What Causes Difficulty In Breathing?

I am a 30 year old female experiencing difficulty breathing. It s as if I can t get enough breath. Onset 5 days, getting gradually worse each day. Only other symptom is bloated a little. When i take a breath and look in the mirror, I can see my throat area of my neck sink in very deeply. I can feel it sinking in and then my breast bone area puffs out. (sorry about explanation, hard to explain) Very concerned. Have no health issues. Should I be worried?