Another only child here! And it is a blessing to enjoy your own company.
I have learned that there is absolutely nothing anyone can do to get an alcoholic to stop drinking. The futile attempt almost killed me.
I left my ex abf when he was active, but I did not go no contact until he had 6 months sober. You never know how things will work out. The end of the actual drinking is just the very beginning of a very long hard road to recovery.
Leaving was so painful. You have already put that distance between you and your A. Good for you. Use this time alone well. Get to know yourself; it's fun. Learn to enjoy your own company. If he is the one, it will keep. Hang on to your peace; make it count. Take care of you.