Agreed, it's definitely worth the effort to try to figure this out now. I would say that based on what you said about not being able to stop, or not being able to stick to previous limits, that's kind of answering your own question-- yes, it's a problem not to be able to do those things. It's better to have a choice about how much alcohol you drink instead of it just being based on how much is around... Because if you're drinking like this now, guess what is going to happen when you're under lots of stress and can't think of a way to blow off steam. A lot of people start with a small problem and let it get big. I would recommend doing what you're doing now and trying to figure out to what extent it might affect you if it goes on.
http://www.alcoholscreening.org/Home.aspx (They ask for a zip code but you can put any old numbers...)