I found getting and staying asleep was very difficult, especially the first night. The worst was the guilt and shame and my mind would be running at 1000 mph. Most people I have spoken to have the same experience.
Well done for speaking to someone, it's a huge step forward and you will need the support. My biggest problem was accepting and acknowledging my alcoholism and it's great that you are doing that.
I really hope you get some rest tonight and remember that you will feel better tomorrow