It's normal for some people to drink the amount you do, yes.
However, we don't ask if our behaviour is normal unless we're unsure about it. I'm a recovering alcoholic and I also can't just have one drink, because I can't stop at one (over 1 year sober!).
Does this mean you're an alcoholic? Not necessarily, however I would classify your drinking as 'binge drinking', which does count under an 'alcohol use disorder' spectrum.
I think we often think of people who abuse alcohol as people who drink to excess daily, but in reality it's a progressive disease and full dependency is really one of the later stages. I could certainly go all week without drinking, until one day I couldn't, however, this isn't true for everyone.
I would recommend watching Adrian Chiles documentary drinkers like me, which is on youtube, it's a documentary focused around middle aged and middle class drinkers, might give you some food for thought.