Using alcohol as a way to ease stress does not mean you are alcoholic. Alcoholism has to do with losing control after one starts to drink. It's not the reason why a person drinks--for alcoholics there are no reasons. It's what happens to a person physically after they start drinking.
My suggestion would be to buy a copy of Alcoholics Anonymous and start with The Dr's Opinion. If you can identify with this book, more than likely you are alcoholic. Alcoholics tend to relate very easily. I have met a handful of non-alcoholics who did not relate to it.
Hope this helps.