Would you call me an alcoholic?

Just by the fact that you have to ask this question means you are questioning yourself. I don't doubt that nothing will change in your habits but I think your drinking will accelerate. You say "it's fun and because it acts as a social lubricant". You also state that you are "extremely introverted when sober". So in answer to your question, I would say YES. But as you say "Drink on my lads".