I agree with Kateycatt, and find that your breathing issues are very similar to mine. Even though i am a heart worrier, I always feel short of breath. I had my septum fixed and my tonsils out, and they thought that would help, but I think my sinuses are so blocked. I am always stuffed up, and I'm allergic to just about everything in the air.
Just remember that sometimes because our bodies are so sensitive, and we are so sensitive to our bodies, any little thing can start our anxiety going. Our bodies are so sensitive to the "fight or flight" response that even the smallest of what we think is abnormal starts the anxiety chain. So you may be stuffed up, which causes our breathing to be a little off. Then our mind tells us that there is something wrong, so our breathing then becomes even worse from just thinking about it. Like Kateycatt said, our mind can do amazing things, and it's not always good.