My separated AH and I share a 4 year old daughter too. I sounded like you before. Id say what a great father he was when sober, etc...Truth is, a really great father takes care of himself and leads by example. I hurt and cry when I think of the ride my daughter is in for because of her alcoholic father. I have to share in responsibility that I had a child with him. Focus on you and her and hopefully if he finds sobriety over a long period of time, things can work. Until then, care for yourself.