What Is The Cause And Treatment For Panic Attack?

I believe I had a panic attack Monday night it is now saturday. I have been having heart palpitations sweating chills vomiting and diarrhea all week. It just comes on for no reason. I am 29 about 5 foot 2 inches 140 lbs. I had blood work done and an ekg everything was normal. Can u help me. The dr put me on a medicine for acid reflux and for an intestinal ulcer.