Hi There
My wife suffers from panic attacks. I think yours maybe more anxiety than full blown panic attack.
Tips: -
Sit still with your eye's closed and breathe slowly. Breathe in for 4 seconds, then out for 5 seconds.
If you are having problems breathing it sounds like you could be hyperventilating. Try breathing into a paper bag, to replace the carbon dioxide you my be loosing. You may get some funny looks but who cares.
If you think it is very uncomfortable for you then please seek medical advice. I know I am from the UK, but i am sure there are very good therapists out there how could help you.
Please keep us up to date.