Panic attack maybe,stress can also irritate stomach,natural yogurt might help.Being out of breath can also be a sign of anemia,not all docs check this as a routine.Also check side affects of any meds!
Obviously you're having an anxiety attack
If your stomach is bloated, have you considered digestive related concerns? Sometimes digestive symptoms can make someone feel as though they are experiencing anxiety or heart related problems - which, in turn, also yield anxiety ..... just a thought ....
I have had anxiety problems for quite awhile now and the feeling of my throat being constricted is something I have felt often. I do not have stomach bloating but have had intestinal distress and almost constant diarrhea plus some other not so fun symptoms. Blood test were also inconclusive for me. I have found that getting out and walking has been the best help for me. I have a dog that I take on a walk at least once a day at least 2 miles. Some days I feel like I cannot but just push through it, for me I self focused to much and stressed myself out! Pushing towards new goals in life have been very helpful too.
Talking with someone may be helpful also, if anxiety is your main problem and not just a symptom of something else, counselors are often quite helpful in learning new coping mechanisms.