Breathing feels weird when I focus on it

I have anxiety about breathing. It’s stupid I know, but it’s a thing for me.

I can’t describe it. I’m not short of breath, I can still take deep breaths and my breathing still sounds normal. It’s not fast or slow. It doesn’t happen when I’m not thinking about it. It just feels like there is something wrong with it.

I went to the doctor about it when I was 12 or 13 and she said my breathing was fine. I’m 28 now and it’s been happening on and off since then. It doesn’t get worse when exercising which is weird. If anything, it gets better.

This pops up every once in a while, usually when stressed, sometimes after an illness (or both at the same time; I get sick more when I’m stressed).