Feel I can't get enough air???

:huh:Can anyone help me? Why do I feel the need to take a deep breath all the time? which makes me concentrate on my breathing to much, Ive tried to do 'cleansing' breathes but this seems to make it worse. I am starting to recover from my health and general anxiety with some cbt but this hurdle I can't seem to get over, it sets me back to thinking I am ill. Thank you

I would also like to add that I wake in the night gasping for air, mainly when I'm laid on my back