Hi,
I have the same symptoms. I feel like I can't breathe. Think I'm not breathing. Think my throat is closing. Its a horrible feeling. I am still trying to deal with it also. Some days I do better than others. My neck will sometimes hurt because of the way I am breathing because I start to panic breathe. I would try some breathing exercises. Sometimes they help me but sometimes I can't get the non breathing out of my head either. Just keep trying :) you can do it! And know that you are not alone with these symptoms.
Summer7