Breasts too big?

An

So I'm a little concerned. I've noticed that when I start running or walking fast paced I run out of breath really quick. It's even a little difficult to breath fully just sitting here with my 3 sports bras on. I'm not even tired when exercising, I literally can't get a good breath in and start heavy breathing like I'm EXTREMELY out of shape. I'm a 34 G and actually growing out of that size.

Is it possible my breast size is constricting my lungs ability? Does insurance cover reductions? Should I get a reduction? I can't even find a proper sports bra in my size to keep the boobs in place.