Breathing exercises, meditation, proper diet, therapy, sometimes medications, and many, MANY other things can help you with this! There are some great books- From Panic To Power
By Lucinda Bassett, The
Anxiety Diet,
and the Idiots Guide To Anxiety are just a few great self help books for anxiety/panic. Search Anxiety and Self Help on Amazon. There are many of us here who've been where you are. Feel free to post whenever you need help, someone to talk to, have a question, whatever!