Puffy-
Sweetie, I'm really sorry you are hurting so badly. Only you know what your "deal breaker" is, and alcoholism is certainly in my opinion a wise deal breaker to have.
I had to come to a decision after marrying my husband about his alcoholism and had to give him an ultimatum. It was a hard thing to do (we had two young children also). I had to make a choice that really hurt me, but I had two children to think about, and I knew my husband would continue with his drinking if I didn't put a stop to it. He was never mean or abusive when he drank, but he did have a problem and talking about it didn't help.
I told him he had to make a choice between his family or his alcoholism. He moved out for about a month, but he decided his family was most important and he made the choice to stop cold turkey. He's been sober for many years now and our family is stronger than ever.
You may have to make this choice, because it sounRAB like talking isn't helping and if your fiance isn't ready to realize and admit he has a problem, then he isn't ready to face and go through recovery. It's best to make this choice before marrying. Until he is ready nothing you say will help, and by talking him to death yet staying with him, it gives him no reason to quit for now. Maybe actually losing you will open his eyes.
You see, he isn't suffering right now- you are and it's not healthy or fair that you suffer because of his addiction.
I wish you and your fiance the very best.