Welcome to SR. Congrats on stopping the other addictions.
I personally was not able to successfully plan a future date to quit drinking. For me, that was just a way to keep drinking currently. But I assume it must work for some people.
For me, it helped to think about why I wanted to be sober and strengthen that motivation. Posting here and finding a good therapist and at times going to support groups helped me.
I did not drink a ton and I stopped fairly early.