Why is it that every time i smoke cigarettes my mind races & my anxiety heavily increases?

It's the nicotine: Nicotine is a stimulant, and stimulants are likely to worsen anxiety. It can make you jumpy, jittery, and anxious even if you don't have anxiety. If you have anxiety, it can make it worse. A stimulant is the opposite of some of the types of drugs that treat anxiety. Besides the nicotine, cigarettes have many other unhealthy chemicals that are bad for you. Of course, I recommend you quit smoking.