Anxiety can be real bad. It will start subsiding as you go along. As marcatj suggested, there are natural ways to reduce or stop it. End your addiction now, the book has formulas to help this too.
there is a homeopathic remedy called Calms Forte.. they are little pills made of herbs and stuff that you take a couple times a day that are specifically for ansiety... they help.
also - i find journaling helps alot for my anxiety... just getting it out of my body and putting it down on paper. it has an amazing calming effect...