Hey barralba, thank you for sharing your story. It amazes me to see how many stories are similar to mine. I was in a relationship with my ex fiancé for two years, and she also seemed to be a Dr. Jekyll and Mr. Hyde when it came to alcohol. Her incidents were also few and far between at first, and they only caused minor embarassment to me, again, at first. She didn't turn into Mr. Hyde every time, either. I also felt that our relationship was 90% happy, and she was a great person when sober. The thing is, alcoholism is a progressive and fatal disease. After we got engaged, her drinking habits worsened to the point where she practically destroyed our relationship with her drunken behavior and infidelity while drunk, and she put my life in danger. She became even more verbally abusive in general and when I tried to talk to her about her habits. She also started using drugs more frequently. She never listened to me. I chose to leave and wrote her a letter explaining why I left. Now, it's up to her to change if she wants to.
Your story really helped me put my own in perspective. I would definitely encourage you to read the other stories that you find here, as that has helped me a lot. I've been going to 12-step meetings and counseling. I've also been reading two books: "Codependent No More" and "Beyond Codependency" by Melody Beattie. They have been most helpful.
Again, thank you for having the courage to share your story. Admitting there is a problem is the first step on the road to getting better.