I Love My Ex And Want him Back?

My ex is an alcoholic/drug abuser, but we have 2 kids together and I still love him. I miss him terribly, he walked out on me while I was pregnant with our third child (which sadly passed away at birth). He believes that Iam dating one of his friends (I’m not) and he won’t speak to me and all I want is for him to come home. Can anyone help me out with this?