I work with a lot of drinkers and I believe they would think there's something wrong with me if I told them I've stopped drinking. But to be fair, at our Christmas lunch, a colleague and I had orange juice and no one blinked an eye.
Some of your colleagues sound very rude but then again I know how I behaved when I had a drink down me.
Try not to be too downhearted, stand by your decisions and look them firmly in the eye.