Do the excercise that you love. Eat healty food, read everything what you eat. Just dont eat everything that is "good for you", first read and learn about healty lifestyle and food...
I have panic attacks too. During them i try to breath normaly and im telling myself that everything is going to be allright. I know its hard but i just try to think positive. Meditacion and yoga helps too
I was smoking cigarets for about 6 years, then my brother buy me eletronic cigaret and i quit smoking in about week. So i think if you want to quit smoking cigarets then its eletronic cigaret great choice..