Based on what you described, I would have to say that does sound very much like a panic attack to me. Panic attacks tend to be different per individual and can manifest physically/emotionally in many ways. For instance, I have had several different "types" of panic attacks ranging from the mild shakey-fearful to the full-blown "heart-attack-can't-breathe-think-I'm-gonna-die" kind. Either way, panic attacks can be downright scary at times and one thing to keep in mind no matter what is that they will not harm you even if it feels like they will.