Thanks to all of you for your concern and responses. I originally posted this thread to admit my relapse, which I felt was the right thing to do. So I'm back to day two again today, and that's a place to start.
I take full responsibility for drinking Saturday night, and while I know other people cannot make us drink, I also know some people make us very thirsty for a drink. The argument that eventually led to my choice of going out to get drunk was not an isolated incident, but instead was the culmination of several arguments, each a small trigger in a series of triggers that ultimately led me to say "to hell with this< I'm outta here". It's like being in a drama setting for days on end, and trying to walk on egg shells so as not to spark another argument. I made the decision to allow this roommate to move in, and now it bugs me daily. Not just the distinction of boundaries being blurred, but the little things as well, such as her sleeping all day, up all night, panties lying on the living room floor, just those kinds of things, and nothing is being done when she says she'll do it. I don't know what to expect from her when she says she'll do something, which is something that I'm trying to change in my own life, being responsible and accountable for what I say. Her constant mood shifts and changes in her plans leaves me unsettled and uncertain as to what to expect. It's hard to ignore her, because she is staying with me for the time being, but this is going to change soon, because I don't want this to continue. I don't want to be unfair, but will have to insist that she find another place to stay. I've been reluctant to discuss the matter with her due to not wanting to endure another argument, bout of tears and so forth. Geez, how did I let this happen? I must have been in a fog at the time.
Anyway, day 2 again, and I'm drinking coffee. Now I know it is best for me to learn to appreciate being alone, because the drama isn't worth it.