Thanks for the support and suggestions so far. I really appreciate it. I know that I need to focus on myself and the baby right now, and maybe it does make the most sense to let him begin his initial journey alone of getting support to quit. Maybe I should not preoccupy myself with following through on my ultimatum immediately, which I now understand was insufficiently defined in the first place.
In reading more about this problem, it really saddens me to learn how predictable the pattern can be with alcoholic partners. It makes me feel little hope for our future, which makes it difficult to focus on the baby and be happy about anything. I knew there was a problem, but I underestimated the seriousness of it. I told myself that he has more control than most people, and that he would never be willing to lose his family to his drinking. I allowed myself to not think of it as an incurable disease, rather a choice. I definitely need to educate myself more on what it means to be an alcoholic, and what it means to live with one. Then I guess I can redefine my boundaries.
In the meantime, do you think it is going to blunt our chances of success if I let him back into my heart by accepting and sharing his affection? My walls are up right now while I try to figure out what it means to take care of myself and the baby, but to be honest, I don't feel happy or relaxed in this state.