Whats a useful coping tool that is recommended whenever a craving comes into your head? the restlessness and anxiety is unbearable at times as well?

There are several methods to deal with various cravings. One method- a Preemptive Displacement Tactic, is to plan ahead & write down what deliberate Thought/Action One would use to Displace a craving Thought when it comes. For example if craving for Cake - One can have cut to pieces apple/mango/peach ... ready to eat - in place. And if Cigarette Smoking because of Stress - Have a Relaxation Music

It would be helpful to know what you are craving. There are 12 step groups for cravings for substances, sex, food. Please see a Clinical Psychologist with expertise in multiple types of psychotherapy to evaluate your problems and help and recommend If you need medication managed by a Psychiatrist. Get a complete physical exam to find out if the cravings are due to a physical illness or deficit.