Why does alcohol make me anxious?

I’m not a big drinker, but I used to be able to have the occasional drink in social settings. Lately, I have been noticing that whenever I do drink, I get extremely anxious. I had a coworker’s retirement dinner the other night and I ordered a drink since everyone was drinking and it was a relaxed environment. I maybe had 5-6 sips and my anxiety was through the roof. I couldn’t finish the drink. I thought the point of drinking was to make you feel relaxed, not to quadruple my anxiety!