hi
i have been through similar experiences. i had that horrible 'can't get a breath' feeling - the harder I tried the worst it got. That turned into a panic attack - that drowning feeling caused so much anxiety that there was a hugh adrenhalin rush (because it's frightening as hell) which meant fast heart, over breathing - too much oxygen -> dizziness, etc. There were 2 basic problems casusing all this - gas bloat/contropation in which physically made it harder for the diaphragm to work -> chest breathing. Also general anxiety meant I was holding my abs tight which also restricted my breathing. I went to eh breathing specialist and got training in how to use my diaphragm properly - of course i had to sort out the gut and anxiety too. Chest breathing was habitual with me and it took a long time to train myself to breath properly all the time. Daily exercises and deliberate think about it eventually led to it becoming automatic. Life's a lot happier without all that stuff going on. Try reading about hyperventilation syndrome. good luck.
This could be anxiety, possibly with vocal cord dysfunction. However the "adrenaline rushes type feelings,
Your symptoms match mine to the letter. My doctor thought that I had asthma but when my symptoms did not improve with the medications he prescribed I went back, since then I have had 24hr BP testing ECG
oh sorry I was ment to say that be constapated can cause a hatial hernia as all the pushing can cause the stomach or part of it to go up into the chest cavity. look for links for the hatial hernia on the internet