You had yourself a panic attack. They happen out of the blue and that is why we "Panic" This has done no harm to your body, just a little scary. Your mind starts to convince itself that there is something drastically even fatally wrong when really it is all in our heads. You calmed down after a while and things went back to normal which means there was not anything seriously wrong with you. Don't worry about it too much. Happens to almost everyone at some point. Read up on the sypmtoms of a panic attack and you will see you had a very natural reaction.
Sure sounds like my first anxiety attack I had in 1997. At that time, I had no idea what was wrong. But, anxiety can be subconscious and creep up on you out of the blue. Trust me....been there! If you have had a check up with the Dr. and everything was fine, then in my opinion you def had an anxiety/panic attack. Key point....when you begin to feel this come on again, try and not fear it. Just allow yourself to feel the feelings and float with it. It will not harm you! After time, it will quit happening all together. When you fear it, it gets worse and it manifests itself in many different ways. For 11 years of my life I thought my anxiety was a heart problem. It wasn't until recently that I resolved that thought/issue. YOU WILL BE OK! DONT BE AFRAID OF IT!