Ok I'm going to come at this from a totally different angle as I honestly feel like I am cured (or 95% better).

I'll start from the beginning - I had exactly the same as it's been explained on here - felt like I could never get a satisfactory (deep) breath and when I did it was instant relief until the feeling would come again a couple of minutes of later and I'd have to do it again (which I couldn't always get the perfect deep breath and I would keep trying until I did when I'd get instant relief until a minute later). It started to consume my every thought - there wasn't a day went by when I wasn't thinking or 'feeling' about my breath. It was affecting my whole life, particularly my sleep. After about 3 weeks I went to the doctor (who prescribed me some sleeping tablets as I was at my wits end). From there I had lung x-rays, spirometry tests, heart tests, a brain MRI, was prescribed valium, anti-depressants, went to a psychologist, went to a respiratory physiotherapist, went to a buteyko instructor (only breathing through your nose), I even got hypnotised!! This all went on for a period of around 18 months and no-one could work out what was wrong with me (and nothing medically showed up).

I then started to think maybe this was psychological - I had never had any anxiety previously (I am in my mid 50's) or basically any medical issues my entire life. I would be the last person you would call stressed or anxious! Anyway after doing weeks and weeks of research I now honestly believe I had a form of OCD called sensorimotor OCD. It all started when I woke up in the middle of the night and tried to take a deep breath and couldn't and it totally stressed me out. I managed to go back to sleep but the first thing I thought of when I woke up was whether I could take the breath again and that's where it all started - it basically didn't stop from that morning on. I believe for some reason at that moment in time my brain held on to that anxiety of that feeling and the only thing that would relieve it was to take a deep breath.

I believe the urge to take the deep breath is the obsession and the taking of the deep breath is the compulsion that relieves the anxiety of the obsession. From there it just goes around and around in a big circle forever until you treat it. It's no different to feeling an urge to wash you hands and relieving the anxiety by washing your hands until you get the feeling again to wash your hands 2 minutes later.

In saying all this there are not a lot of 'medical' professionals who know about other forms of OCD. If you google sensorimotor OCD (blinking, swallowing, breathing) you will find it is quite a common thing. The way I have helped myself (and this has taken a good 6 months and I'm still going) is just to learn to sit with the (terrible) feeling of needing to take the breath and gradually the anxiety that goes with it has just lowered and lowered. I started running and doing spin classes again even though that terrified me because I thought I wouldn't be able to breath. I've literally changed the way I think - I don't let it stress me out - if I need to take a deep breath I do it without judging myself (everyone takes deep breaths at sometime during the day they just don't have a second thought about it). The whole aim is to lower the anxiety that goes with the thought/feeling of constantly needing to think about controlling your breathing. I know for a fact there is nothing medically wrong with me (after having literally my entire body scanned/checked) and I sleep all night (now) obviously without needing to take a deep breath so it was just a very slow process of turning my thinking around. I had to let go of the belief that there was going to be some magic medication that was going to fix me. It's a very slow process but it 100% does work.

I am now not taking any drugs, exercising and basically enjoying my life. Previously even just thinking back to how I felt I would start to get the feeling in my throat/chest that I needed to relieve by taking a very deep breath but now I can think about it without getting that feeling.

I hope this helps someone - it is a terrible feeling to live with constantly and if you let it it could totally take over your life (which is what OCD does).

Good luck.