Sorry you are sad. You sound really good, though. You have been thinking about how you want your life to be, and that's important.
One of the things that strikes me when posters to this site describe situations like yours: they are not only missing the person they are no longer with, as imperfect as he/she is. .They are also grieving for the life they thought they were going to have with the alcoholic partner. That can be hard to let go of.
Like most anything, it's process. And it takes time. All will be well after a while.