I am quite a regular drinker for the past few years, more than 3 drinks, 3 times a week, i have suddenly decided to stop, have intense anxiety?

See a doctor: First of all, great work deciding to stop! That being said, you may be experiencing withdrawal symptoms, which can start with shakiness and anxiety, and can progress to hallucinations and seizures. Sometimes, medications are necessary to mitigate these symptoms, so you may want to consider seeing your doctor. Hope this helps!

In addition to the previous answer, anxiety can be a common withdrawal symptom. Additionally, many people use alcohol to cope with their anxiety. If that was the case for you, it is important to find alternative, healthy means of coping. Talk to a therapist to help you find healthy and effective ways to cope!