Was it the right decision?

Well good for you in making on your word. You were living in a fantasy, really. While you were first unfortunate enough to think you knew enough about someone to get engaged to them in 13 months, you also made the mistake of falling in "pseudo-love" with an alcoholic. Now let me tell you something about these guys, when it comes to you, and alcohol.. its alcohol. You may be nice, and sweet, and well to put it crudely (****-able) however, alcoholism is an addiction, and unless you are willing to cart him though it and deal with his relapses, your only chance at happiness is to grow a pair of **** (man-balls[that's respect]) and try your hand at love again.