I have these too, but in a milder form. I have Panic Anxiety, Ross, and I get those feelings a lot, along with the racing heart, and the sleeplessness, and often even actual breathing and hyperventilation issues.
I've been learning to control it for years, and doing a fair job of it. I bought the book "Don't Panic" by H. Reid Wilson, and that was the best thing I did for mine.
Hang in there, we're all here for you, and I understand how you feel!
Nightowl >8#