Welcome to SR Kev. You are in good company here.
Different people react differently to withdrawing from alcohol. In some people, the withdrawal effects can be severe and sometimes dangerous. You should get medical advice and/or assistance to detox. That detox process can take a few days or a week, I think, but everyone is different.
After that, it will be really helpful to make a NOT drinking plan. After years of abuse it can take a while to feel right about not drinking. A plan helps. You can read around the forums here and ask questions. Members here are using many different methods/plans to stay sober. Members here are also very helpful, and will be glad to help you find your path to permanent sobriety.
You can do this.