Yes your heartbeat might be a little different because your mind is exaggerating what is happening. In all likelihood you are not going to die though, you have to remember its your mind thats effecting your heart not your heart effecting your mind, and very often its fear of something that isn't really founded in reality.
YES YES YES! All of these things you explain are classic anxiety symptoms.
PLEASE try to think positively, and accept that it is anxiety...and that there is nothing wrong with you physically. I know the sensations are very frightening, but I promise you they are not harmful.
Hang in there...work on the anxiety...read the forum....maybe invest in a few books...anything that will help you start to conquer this. I know it's tough...but don't dwell on this last incident. It was one episode and it's over now.
Take Care!