Shortness of breath

Does anyone ever feel like they are not getting enough oxygen or breathing underwater. This has been getting worse and worse for me till now its almost an all day thing. My DR says its anxiety. I'm not gasping for breath but I sometimes feel like if I could yawn I would feel better.

Thanks for the replies guys. I am learning to do the technique with the Lucinda Bassest program. I think the 2/4 breathing will help more and more once I remember to do it.