Thank you for letting everyone know you are doing much better. So many reading your post will be helped by your sharing your own experience and your recovery.
A childhood friend of mine was the son of an alcoholic father. The father walked out on his family and went to live in another country. The son was a teenager when the father left.
He wrote to his father many letters over the years. But they were never answered.
When his father finally died, the son was by then in his 30's.
Under the father's bed--found after the father's death-- was a box containing all the letters his son had written to him. Unopened.
Alcoholics are very good at cutting people off, as your AH has done. I expect the professionals might give explanations for why alcoholics do this.
But in the end, abuse is abuse.
You didn't cause it.
Please continue to take good care of your life.