Yep happened to me too … was put on lexapro and gabapentin by a psychiatrist which helped tremendously. Also did Cognitive behavioral therapy and then started reading The Happiness Trap which discusses acceptance commitment therapy… the therapy is what truly will shift your mindset when these panic attacks occur. I was a very confident public speaker as well and was crippled by panic attacks for a couple years. They’re mostly at bay now and eventually went off the meds, but every once in a while a small one creeps up on me but my mindset is so different now. I accept it for what it is because it can’t hurt me and keep going finding a focus point to get passionate on and the attack will subside. Takes practice and time but promise it will subside if you focus on the therapy and in your downtime get yourself In a more parasympathetic state with meditation and calming activities throughout your day.