Hi Retep. You are asking, 'Where to begin?' You've already begun, you've posted here on SR, and in the Secular Connections forum, a place I consider to be an excellent one to choose for your last beginning. There are some good posts pinned to the top of the forum, and I suggest you read those and the discussions that follow. This might lead you to ask even more questions, leading to deeper insight.
I used the term 'your last beginning' there, and I hope you find it an interesting choice. This most definitely can be the end of your quest for a permanent, unconditional sobriety. You can take your self doubt and anxiety and pack them up, replacing them with an iron determination that nothing can ever shake. So, are you ready to make that final decision about ever using alcohol? You CAN do this, Retep. It really is up to you. Onward!