Is nicotine harmful? if, not does it cause any other issues other than addiction? is there any substance in e-cigs that are harmful to your health?

Nicotene harms. : Yes, nicotene use risks cancer, heart and lung diseases. With e-cigs, jury is out, tho' unregulated variety of products make use quite a risk since might contain variety of harmful products. Try chewing gum instead or give clnical hypnosis a try for quitting urge to smoke anything; displace anxiety to, say, twirling a pen or coins in pocket.