I guess I'm wondering what is so difficult about not drinking alcohol? You obviously wanted to drink, so since you couldn't get your usual vodka, you settled for wine. You're not used to wine, so it's not unusual that you don't chug it down like you did vodka. Of course, if you continue to buy wine, you will eventually get used to it and will no longer stop at one glass.
While it's true none of us can definitely confirm that you are an alcoholic, don't forget that you are posting on a forum full of alcoholics and we have all been where you are now. We have all tried different things to convince ourselves that we aren't alcoholic, but in the end, it comes down to acceptance. When we stop fighting the idea (and deep down knowledge) that we just can't drink alcohol responsibly, life gets a lot easier
So, again, I ask...what is so difficult about not drinking alcohol?