Sometimes, something extra painful happens, and it feels like my heart is about to explode. The pain in it travels down my arms and through my organs.

I can't stand up during this, I'll usually be writhing on the floor as my muscles tense and convulse. 

I stop being able to breathe and begin choking and suffocating until I'm near-passed out or actually out cold. 

I can't name a worse feeling than this.